Main Street Capital Corporation
(Exact name of registrant as specified in its charter)

Indicate by check mark if the registrant is a well-known seasoned issuer, as defined in Rule 405 of the Securities Act. Yes o No þ

Indicate by check mark if the registrant is not required to file reports pursuant to Section 13 or Section 15(d) of the Act. Yes o No þ

Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days. Yes þ No o

Indicate by check mark whether the registrant has submitted electronically and posted on its corporate Web site, if any, every Interactive Data File required to be submitted and posted pursuant to Rule 405 of Regulation S-T during the preceding 12 months (or for such shorter period that the registrant was required to submit and post such files). Yes o No o

Indicate by check mark if disclosure of delinquent filers pursuant to Item 405 of Regulation S-K is not contained herein, and will not be contained, to the best of registrant's knowledge, in definitive proxy or information statements incorporated by reference in Part III of this Form 10-K or any amendment to this Form 10-K. þ

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer or a smaller reporting company. See the definitions of "large accelerated filer," "accelerated filer" and "smaller reporting company" in Rule 12b-2 of the Exchange Act.

Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act). Yes o No þ

The aggregate market value of the registrant's common stock held by non-affiliates of the registrant as of June 30, 2010, was approximately $184.0 million based upon the last sale price for the registrant's common stock on that date.

The number of outstanding common shares of the registrant as of March 9, 2011 was 18,881,544.

Portions of the registrants' definitive Proxy Statement for its 2010 Annual Meeting of Stockholders, to be filed with the Securities and Exchange Commission, are incorporated by reference in this Annual Report on Form 10-K in response to Part III.

This Annual Report on Form 10-K contains forward-looking statements regarding the plans and objectives of management for future operations. Any such forward-looking statements may involve known and unknown risks, uncertainties and other factors which may cause our actual results, performance or achievements to be materially different from future results, performance or achievements expressed or implied by any forward-looking statements. Forward-looking statements, which involve assumptions and describe our future plans, strategies and expectations, are generally identifiable by use of the words "may," "will," "should," "expect," "anticipate," "estimate," "believe," "intend" or "project" or the negative of these words or other variations on these words or comparable terminology. These forward-looking statements are based on assumptions that may be incorrect, and we cannot assure you that the projections included in these forward-looking statements will come to pass. Our actual results could differ materially from those expressed or implied by the forward-looking statements as a result of various factors, including the factors discussed in Item 1A entitled "Risk Factors" in Part I of this Annual Report on Form 10-K and elsewhere in this Annual Report on Form 10-K. Other factors that could cause actual results to differ materially include changes in the economy and future changes in laws or regulations and conditions in our operating areas.

We have based the forward-looking statements included in this Annual Report on Form 10-K on information available to us on the date of this Annual Report on Form 10-K, and we assume no obligation to update any such forward-looking statements, unless we are required to do so by applicable law. However, you are advised to consult any additional disclosures that we may make directly to you or through reports that we in the future may file with the SEC, including subsequent annual reports on Form 10-K, quarterly reports on Form 10-Q and current reports on Form 8-K.

Main Street Capital Corporation ("MSCC") was formed on March 9, 2007 for the purpose of (i) acquiring 100% of the equity interests of Main Street Mezzanine Fund, LP ("MSMF") and its general partner, Main Street Mezzanine Management, LLC ("MSMF GP"), (ii) acquiring 100% of the equity interests of Main Street Capital Partners, LLC (the "Investment Manager"), (iii) raising capital in an initial public offering, which was completed in October 2007 (the "IPO"), and (iv) thereafter operating as an internally managed business development company ("BDC") under the Investment Company Act of 1940, as amended (the "1940 Act"). MSMF is licensed as a Small Business Investment Company ("SBIC") by the United States Small Business Administration ("SBA") and the Investment Manager acts as MSMF's manager and investment adviser. Because the Investment Manager, which employs all of the executive officers and other employees of MSCC, is wholly owned by us, we do not pay any external investment advisory fees, but instead we incur the net operating costs associated with employing investment and portfolio management professionals through the Investment Manager. The IPO and related transactions discussed above were consummated in October 2007 and are collectively termed the "Formation Transactions."

On January 7, 2010, MSCC consummated transactions (the "Exchange Offer") to exchange 1,239,695 shares of its common stock for approximately 88% of the total dollar value of the limited partner interests in Main Street Capital II, LP ("MSC II" and, together with MSMF, the "Funds"). Pursuant to the terms of the Exchange Offer, 100% of the membership interests in the general partner of MSC II, Main Street Capital II GP, LLC ("MSC II GP"), were also transferred to MSCC for no consideration. MSC II commenced operations in January 2006, is an investment fund that operates as an SBIC, and is also managed by the Investment Manager. The Exchange Offer and related transactions, including the transfer of the MSC II GP interests, are collectively termed the "Exchange Offer Transactions" (see Note J to the consolidated financial statements). As of December 31, 2010, an approximately 12% minority ownership in the total dollar value of the MSC II limited partnership interests remained outstanding, including

approximately 5% owned by affiliates of MSCC. We have submitted an exemptive relief application to the SEC to permit us to acquire the approximately 5% ownership in the total dollar value of the MSC II limited partnership interests held by affiliates of MSCC. There can be no assurance that we will obtain the exemptive relief or that if we do obtain such relief it will be obtained on the terms we have outlined in our request.

MSCC has direct or indirect subsidiaries that have elected to be taxable entities (the "Taxable Subsidiaries"). The primary purpose of these entities is to hold certain investments that generate "pass through" income for tax purposes. The Taxable Subsidiaries are each taxed at their normal corporate tax rates based on their taxable income.

Unless otherwise noted or the context otherwise indicates, the terms "we," "us," "our" and "Main Street" refer to MSCC and its subsidiaries, including the Funds and the Taxable Subsidiaries.

As part of the Formation Transactions, the Investment Manager, which employs all of the executive officers and other employees of MSCC, became a wholly owned subsidiary of MSCC. However, the Investment Manager is accounted for as a portfolio investment of Main Street, since the Investment Manager is not a registered investment company and since it conducts a significant portion of its investment management activities for parties outside of MSCC and its consolidated subsidiaries. The portfolio investment in the Investment Manager is accounted for using fair value accounting, with the fair value determined by MSCC and approved, in good faith, by MSCC's Board of Directors. MSCC's valuation of the Investment Manager is based upon the discounted net cash flows from third party recurring management, consulting and advisory fees. For more information on the Investment Manager, see "Note D — Wholly Owned Investment Manager" to our consolidated financial statements.

In connection with the Formation Transactions, MSCC entered into a support services agreement with the Investment Manager. The agreement requires the Investment Manager to manage the day-to-day operational and investment activities of Main Street. The Investment Manager generally incurs all normal operating and administrative expenses, except those specifically required to be borne by MSCC, which principally include costs that are specific to MSCC's status as a publicly traded entity. The expenses paid by the Investment Manager include the cost of salaries and related benefits, rent, equipment and other administrative costs required for Main Street's day-to-day operations.

The Investment Manager is reimbursed for its expenses associated with providing operational and investment management services to MSCC and its subsidiaries. Each quarter, as part of the support services agreement, MSCC makes payments to cover all expenses incurred by the Investment Manager, less amounts the Investment Manager receives from third party management, consulting and advisory fees.

Our principal executive offices are located at 1300 Post Oak Boulevard, Suite 800, Houston, Texas 77056. We maintain a Web site on the Internet at www.mainstcapital.com. We make available free of charge on our Web site our annual reports on Form 10-K, quarterly reports on Form 10-Q, current reports on Form 8-K, and all amendments to those reports as soon as reasonably practicable after such material is electronically filed with or furnished to the Securities and Exchange Commission. You may read and copy any materials we file with the SEC at the SEC's Public Reference Room at 100 F Street, NE, Washington, DC 20549. You may obtain information regarding the Public Reference Room by calling the SEC at 1-800-SEC-0330. Information contained on our Web site is not incorporated by reference into this Annual Report on Form 10-K, and you should not consider that information to be part of this Annual Report on Form 10-K.

Our principal investment objective is to maximize our portfolio's total return by generating current income from our debt investments and capital appreciation from our equity and equity-related investments, including warrants, convertible securities and other rights to acquire equity securities in a portfolio company. Our LMM portfolio investments generally range in size from $3 million to $20 million.

We seek to fill the current financing gap for LMM businesses, which, historically, have had more limited access to financing from commercial banks and other traditional sources. Given the current credit environment, we believe the limited access to financing for LMM companies is even more pronounced. The underserved nature of the lower middle market creates the opportunity for us to meet the financing needs of LMM companies while also negotiating favorable transaction terms and equity participations. Our ability to invest across a company's capital structure, from senior secured loans to equity securities, allows us to offer portfolio companies a comprehensive suite of financing solutions, or "one stop" financing. Providing customized, "one stop" financing solutions has become even more relevant to our LMM portfolio companies in the current credit environment. We generally seek to partner directly with entrepreneurs, management teams and business owners in making our investments. Main Street believes that its LMM investment strategy has a lower correlation to the broader debt and equity markets.

We typically seek to work with entrepreneurs, business owners and management teams to provide customized financing for strategic acquisitions, business expansion and other growth initiatives, ownership transitions and recapitalizations. In structuring transactions, we seek to protect our rights, manage our risk and create value by: (i) providing financing at lower leverage ratios; (ii) generally taking first priority liens on assets; and (iii) providing significant equity incentives for management teams of our portfolio companies. We prefer negotiated deals to widely conducted auctions because we believe widely conducted auction transactions often have higher execution risk and can result in potential conflicts among creditors and lower returns due to more aggressive valuation multiples and leverage ratios.

As of December 31, 2010, Main Street had debt and equity investments in 44 LMM portfolio companies. Approximately 77% of our total LMM portfolio investments at cost, excluding our 100% equity interest in the Investment Manager, were in the form of debt investments and 91% of such debt investments at cost were secured by first priority liens on the assets of our LMM portfolio companies. As of December 31, 2010, Main Street had a weighted average effective yield on its LMM debt investments of 14.5%. Weighted average yields are computed using the effective interest rates for all debt investments at December 31, 2010, including amortization of deferred debt origination fees and accretion of original issue discount. At December 31, 2010, we had equity ownership in approximately 91% of our LMM portfolio companies and the average fully diluted equity ownership in those portfolio companies was approximately 33%.

In addition to our investment strategy of investing in LMM companies, we opportunistically pursue investments in privately placed debt securities. Our private placement investment portfolio primarily consists of direct or secondary private placements of interest-bearing securities in companies that are generally larger in size than the LMM companies included in our investment portfolio. As of December 31, 2010, we had privately placed portfolio investments in 16 companies collectively totaling approximately $67.1 million in fair value with a total cost basis of approximately $65.6 million. The weighted average revenues for the 16 privately placed portfolio company investments was approximately $352 million. All of our privately placed portfolio investments were in the form of debt investments and 71% of such debt investments at cost were secured by first priority liens on portfolio company assets. The weighted average effective yield on our privately placed portfolio debt investments was approximately 12.5% as of December 31, 2010.

depressed economic periods. However, we intend to appropriately manage our cost structure and liquidity position based on applicable economic conditions and our investment outlook. The level of realized gains or losses and unrealized appreciation or depreciation will also fluctuate depending upon portfolio activity and the performance of our individual portfolio companies. The changes in realized gains and losses and unrealized appreciation or depreciation could have a material impact on our operating results.

Our investments are made through both MSCC and the Funds. MSCC and the Funds share the same investment strategies and criteria in the lower middle market, although they are subject to different regulatory regimes. See "— Regulation." An investor's return in MSCC will depend, in part, on the Funds' investment returns as MSMF is a wholly owned subsidiary of MSCC and as MSC II is a majority owned subsidiary of MSCC.

During January 2011, we closed an expansion of our three-year credit facility (the "Credit Facility") from $85 million to $100 million. The $15 million increase in total commitments pursuant to an accordion feature under the Credit Facility relates to a new lender relationship which further diversifies the Main Street lending group to a total of six participants. The accordion feature of the Credit Facility allows us to seek up to $150 million of total commitments from new or existing lenders on the same terms and conditions as the existing commitments. The increase in total commitments under the Credit Facility provides us with access to additional financing capacity in support of our future investment and operational activities.

During January 2011, Main Street closed LMM portfolio investments in Pegasus Research Group, LLC (dba Televerde ("Televerde")), and in Van Gilder Insurance Corporation ("Van Gilder"). Main Street's $7.5 million investment in Televerde represents a combination of debt and equity capital invested in the company in order to support the recapitalization and growth financing of the company. Televerde is headquartered in Phoenix, Arizona and provides sales-lead services to Fortune 500 IT hardware and software companies. Main Street's $10.7 million investment in Van Gilder represents a combination of debt and equity capital invested in the company in order to refinance certain debt obligations and provide additional liquidity for the company's ongoing operations. Van Gilder is headquartered in Denver, Colorado and provides a full spectrum of insurance brokerage services including business insurance, employee benefits, risk management and personal insurance services.

During February 2011, Main Street completed a LMM portfolio investment in Principle Environmental, LLC ("Principle"). Main Street's $7.5 million investment in Principle represents a combination of debt and equity capital invested in the company in order to support the recapitalization of the company, as well as to provide additional financing for future growth. Principle primarily serves the oil and gas and transportation industries, and is the leading provider of noise abatement services in the Marcellus Shale oil and gas basin. The company is headquartered in Weatherford, Texas with additional facilities in Pennsylvania.

Our principal investment objective is to maximize our portfolio's total return by generating current income from our debt investments and realizing capital appreciation from our equity and equity-related investments, including warrants, convertible securities and other rights to acquire equity securities in a portfolio company. We have adopted the following business strategies to achieve our investment objective:

Our investment team has identified the following investment criteria that it believes are important in evaluating prospective portfolio companies. Our investment team uses these criteria in evaluating investment opportunities. However, not all of these criteria have been, or will be, met in connection with each of our investments.

Main Street's portfolio investments, as used herein, refers to all of Main Street's LMM portfolio investments, privately placed portfolio investments, and our investment in the Investment Manager and excludes all "Marketable securities and idle funds investments." Main Street's LMM portfolio investments principally consist of secured debt, equity warrants and direct equity investments in privately held LMM companies. Main Street's privately placed portfolio investments consist of debt investments in middle market businesses that are generally larger in size than the portfolio companies within the LMM portfolio.

Historically, we have made LMM debt investments principally in the form of single tranche debt. Single tranche debt financing involves issuing one debt security that blends the risk and return profiles of both secured and subordinated debt. We believe that single tranche debt is more appropriate for many LMM companies given their size in order to reduce structural complexity and potential conflicts among creditors.

Our LMM debt investments generally have terms of three to seven years, with limited required amortization prior to maturity, and provide for monthly or quarterly payment of interest at fixed interest rates generally between 12% and 14% per annum, payable currently in cash. In some instances, we have provided floating interest rates for a portion of a single tranche debt security. In addition, certain LMM debt investments may have a form of interest that is not paid currently but is accrued and added to the loan balance and paid at maturity. We refer to this as payment-in-kind or PIK interest. We typically structure our LMM debt investments with the maximum seniority and collateral that we can reasonably obtain while seeking to achieve our total return target. In most cases, our LMM debt investment will be collateralized by a first priority lien on substantially all the assets of the portfolio company. As of December 31, 2010, 91% of our LMM debt investments at cost were secured by first priority liens on the assets of LMM portfolio companies.

In addition to seeking a senior lien position in the capital structure of our LMM portfolio companies, we seek to limit the downside potential of our LMM investments by negotiating covenants that are designed to protect our LMM investments while affording our portfolio companies as much flexibility in managing their businesses as is reasonable. Such restrictions may include affirmative and negative covenants, default penalties, lien protection, change of control or change of management provisions, key-man life insurance, guarantees, equity pledges, personal guaranties, where appropriate, and put rights. In addition, we typically seek board representation or observation rights in all of our LMM portfolio companies.

While we will continue to focus our LMM investments primarily on single tranche debt investments, we also anticipate structuring some of our debt investments as mezzanine loans. We anticipate that these mezzanine loans will be primarily junior secured or unsecured, subordinated loans that provide for relatively high fixed interest rates that will provide us with significant current interest income. These loans typically will have interest-only payments in the early years, with amortization of principal deferred to the later years of the mezzanine loan term. Typically, our mezzanine loans will have maturities of three to five years. We will generally target fixed interest rates of 12% to 14%, payable currently in cash for our mezzanine loan investments with higher targeted total returns from equity warrants, direct equity investments or PIK interest.

In addition to our LMM debt investment strategy, we opportunistically pursue investments in privately placed debt securities. This private placement investment portfolio primarily consists of direct or secondary private placements of interest-bearing securities in companies that are generally larger in size than the LMM companies included in our investment portfolio. As of December 31, 2010, all of our privately placed

portfolio investments were in the form of debt investments and 71% of such debt investments at cost were secured by first priority liens on portfolio company assets.

In connection with our LMM debt investments, we have historically received equity warrants to establish or increase our equity interest in the LMM portfolio company. Warrants we receive in connection with a LMM debt investment typically require only a nominal cost to exercise, and thus, as a LMM portfolio company appreciates in value, we may achieve additional investment return from this equity interest. We typically structure the warrants to provide provisions protecting our rights as a minority-interest holder, as well as secured or unsecured put rights, or rights to sell such securities back to the LMM portfolio company, upon the occurrence of specified events. In certain cases, we also may obtain registration rights in connection with these equity interests, which may include demand and "piggyback" registration rights.

We also will seek to make direct equity investments in situations where it is appropriate to align our interests with key management and stockholders, and to allow for some participation in the appreciation in the enterprise values of our LMM portfolio companies. We usually make our direct equity investments in connection with debt investments. In addition, we may have both equity warrants and direct equity positions in some of our LMM portfolio companies. We seek to maintain fully diluted equity positions in our LMM portfolio companies of 5% to 50%, and may have controlling equity interests in some instances. We have a value orientation toward our direct equity investments and have traditionally been able to purchase our equity investments at reasonable valuations.

Our investment committee is responsible for all aspects of our investment process. The current members of our investment committee are Vincent D. Foster, our Chairman and Chief Executive Officer, Todd A. Reppert, our President and Chief Financial Officer, and David Magdol, Senior Vice President. Mr. Magdol replaced Curtis Hartman, Senior Vice President, in this revolving seat on the investment committee effective January 1, 2011 and will serve through 2011. Our investment strategy involves a "team" approach, whereby potential transactions are screened by several members of our investment team before being presented to the investment committee. Our investment committee meets on an as needed basis depending on transaction volume. Our investment committee generally categorizes our investment process into seven distinct stages:

Deal generation and origination is maximized through long-standing and extensive relationships with industry contacts, brokers, commercial and investment bankers, entrepreneurs, services providers such as lawyers, financial advisors, and accountants, as well as current and former portfolio companies and investors. Our investment team has focused its deal generation and origination efforts on LMM and middle market companies. We have developed a reputation as a knowledgeable, reliable and active source of capital and assistance in this market.

During the screening process, if a transaction initially meets our investment criteria, we will perform preliminary due diligence, taking into consideration some or all of the following information:

Upon successful screening of a proposed LMM transaction, the investment team makes a recommendation to our investment committee. If our investment committee concurs with moving forward on the proposed LMM transaction, we typically issue a non-binding term sheet to the company. For middle market companies, the initial term sheet is typically issued by the borrower.

The non-binding term sheet will include the key economic terms based upon our analysis performed during the screening process as well as a proposed timeline and our qualitative expectation for the transaction. While the term sheet is non-binding, for LMM investments, we typically receive an expense deposit in order to move the transaction to the due diligence phase. Upon execution of a term sheet we begin our formal due diligence process.

Due diligence on a proposed investment is performed by a minimum of two members of our investment team, whom we refer to collectively as the deal team, and certain external resources, who together conduct due diligence to understand the relationships among the prospective portfolio company's business plan, operations and financial performance. Our due diligence review includes some or all of the following:

During the due diligence process, significant attention is given to sensitivity analyses and how the company might be expected to perform given downside, "base-case" and upside scenarios. In certain cases, we may decide not to make an investment based on the results of the diligence process.

Upon completion of a satisfactory due diligence review, the deal team presents the findings and a recommendation to our investment committee. The presentation contains information which can include, but is not limited to, the following:

If any adjustments to the transaction terms or structures are proposed by the investment committee, such changes are made and applicable analyses updated. Approval for the transaction must be made by the affirmative vote from a majority of the members of the investment committee. Upon receipt of transaction approval, we will re-confirm regulatory compliance, process and finalize all required legal documents, and fund the investment.

We continuously monitor the status and progress of the portfolio companies. We generally offer managerial assistance to our portfolio companies, giving them access to our investment experience, direct industry expertise and contacts. The same deal team that was involved in the investment process will continue its involvement in the portfolio company post-investment. This provides for continuity of knowledge and allows the deal team to maintain a strong business relationship with key management of our portfolio companies for post-investment assistance and monitoring purposes. As part of the monitoring process of LMM portfolio investments, the deal team will analyze monthly and quarterly financial statements versus the previous periods and year, review financial projections, meet and discuss issues or opportunities with management, attend board meetings and review all compliance certificates and covenants. While we maintain limited involvement in the ordinary course operations of our LMM portfolio companies, we maintain a higher level of involvement in non-ordinary course financing or strategic activities and any non-performing scenarios. We also monitor the performance of our private placement portfolio investments; however, due to the larger size and sophistication of these middle market companies, it is not necessary to have as much direct management interface.

We use an internally developed investment rating system to characterize and monitor our expected level of returns on each of our investments.

The following table shows the distribution of our portfolio investments (excluding the investment in our affiliated Investment Manager) on the 1 to 5 investment rating scale at fair value as of December 31, 2010 and 2009:

Based upon our investment rating system, the weighted average rating of our portfolio as of December 31, 2010 and 2009 was approximately 2.3 and 2.4, respectively. As of December 31, 2010 and 2009, we had two and three investments, respectively, on non-accrual status comprising approximately 2.6% and 1.1%, respectively, of the total portfolio investments at fair value for each year then ended (excluding Main Street's investment in the Investment Manager).

While we generally exit most investments through the refinancing or repayment of our debt and redemption of our equity positions, we typically assist our LMM portfolio companies in developing and planning exit opportunities, including any sale or merger of our portfolio companies. We may also assist in the structure, timing, execution and transition of the exit strategy. The refinancing or repayment of private placement debt investments typically does not require our assistance due to the additional resources available to these larger, middle market companies.

We determine the net asset value per share of our common stock on a quarterly basis. The net asset value per share is equal to our total assets minus liabilities and any noncontrolling interests outstanding divided by the total number of shares of common stock outstanding.

Our business plan calls for us to invest primarily in illiquid securities issued by private, LMM companies as well as privately placed debt securities issued by private, middle market companies that are generally larger in size than the LMM companies. These portfolio investments may be subject to restrictions on resale and will generally have no established trading market. As a result, we determine in good faith the fair value of our portfolio investments pursuant to a valuation policy in accordance with the Financial Accounting Standards Board ("FASB") Accounting Standards Codification ("Codification" or "ASC") 820, Fair Value Measurements and Disclosures ("ASC 820") and a valuation process approved by our Board of Directors and

in accordance with the 1940 Act. We review external events, including private mergers, sales and acquisitions involving comparable companies, and include these events in the valuation process. Our valuation policy is intended to provide a consistent basis for determining the fair value of the portfolio.

For valuation purposes, control investments are composed of equity and debt securities for which we have a controlling interest in the portfolio company or have the ability to nominate a majority of the portfolio company's board of directors. Market quotations are generally not readily available for our control investments. As a result, we determine the fair value of control investments using a combination of market and income approaches. Under the market approach, we will typically use the enterprise value methodology to determine the fair value of these investments. The enterprise value is the fair value at which an enterprise could be sold in a transaction between two willing parties, other than through a forced or liquidation sale. Typically, private companies are bought and sold based on multiples of earnings before interest, taxes, depreciation and amortization ("EBITDA"), cash flows, net income, revenues, or in limited cases, book value. There is no single methodology for estimating enterprise value. For any one portfolio company, enterprise value is generally described as a range of values from which a single estimate of enterprise value is derived. In estimating the enterprise value of a portfolio company, we analyze various factors, including the portfolio company's historical and projected financial results. We allocate the enterprise value to investments in order of the legal priority of the investments. We will also use the income approach to determine the fair value of these securities, based on projections of the discounted future free cash flows that the portfolio company or the debt security will likely generate. The valuation approaches for our control investments estimate the value of the investment if we were to sell, or exit, the investment, assuming the highest and best use of the investment by market participants. In addition, these valuation approaches consider the value associated with our ability to control the capital structure of the portfolio company, as well as the timing of a potential exit.

For valuation purposes, non-control LMM investments are composed of debt and equity securities for which we do not have a controlling interest in the portfolio company, or the ability to nominate a majority of the portfolio company's board of directors. Market quotations for our non-control LMM investments are generally not readily available. For our non-control LMM investments, we use a combination of the market and income approaches to value our equity investments and the income approach to value our debt instruments. For non-control LMM debt investments, we determine the fair value primarily using a yield approach that analyzes the discounted cash flows of interest and principal for the debt security, as set forth in the associated loan agreements, as well as the financial position and credit risk of each of these portfolio investments. Our estimate of the expected repayment date of a LMM debt security is generally the legal maturity date of the instrument, as we generally intend to hold our loans to maturity. The yield analysis considers changes in leverage levels, credit quality, portfolio company performance and other factors. We will use the value determined by the yield analysis as the fair value for that security; however, because of our general intent to hold our loans to maturity, the fair value will not exceed the face amount of the LMM debt security. A change in the assumptions that we use to estimate the fair value of our LMM debt securities using the yield analysis could have a material impact on the determination of fair value. If there is deterioration in credit quality or a debt security is in workout status, we may consider other factors in determining the fair value of a LMM debt security, including the value attributable to the debt security from the enterprise value of the portfolio company or the proceeds that would most likely be received in a liquidation analysis.

For valuation purposes, all of our private placement portfolio investments are non-control investments and are composed of direct or secondary purchases of interest-bearing securities for which we do not have a controlling interest in the portfolio company, or the ability to nominate a majority of the portfolio company's board of directors. We primarily use observable inputs to determine the fair value of these investments through obtaining third party quotes or other independent pricing.

Due to the inherent uncertainty in the valuation process, our estimate of fair value for our LMM investments may differ materially from the values that would have been used had a ready market for the securities existed. In addition, changes in the market environment, portfolio company performance and other events that may occur over the lives of the investments may cause the gains or losses ultimately realized on

these investments to be materially different than the valuations currently assigned. We determine the fair value of each individual investment and record changes in fair value as unrealized appreciation or depreciation.

As described below, we undertake a multi-step valuation process each quarter in connection with determining the fair value of our investments, with our Board of Directors having final responsibility for overseeing, reviewing and approving, in good faith, our estimate of the fair value of each individual investment.

As part of the internal valuation process, in arriving at estimates of fair value for LMM portfolio companies, Main Street, among other things, consults with a nationally recognized independent advisor. The nationally recognized independent advisor is generally consulted relative to each LMM portfolio investment at least once in every calendar year, and for new LMM portfolio companies, at least once in the twelve-month period subsequent to the initial investment. In certain instances, Main Street may determine that it is not cost-effective, and as a result is not in its stockholders' best interest, to consult with the nationally recognized independent advisor on one or more LMM portfolio companies. Such instances include, but are not limited to, situations where the fair value of Main Street's investment in a LMM portfolio company is determined to be insignificant relative to the total investment portfolio. Main Street consulted with its independent advisor in arriving at Main Street's determination of fair value on a total of 34 portfolio companies, including 33 LMM portfolio companies and our affiliated Investment Manager, for the year ended December 31, 2010, representing approximately 79% of the total LMM portfolio and affiliated Investment Manager investments at fair value as of December 31, 2010. Main Street consulted with its independent advisor relative to Main Street's determination of fair value on 8, 10, 8, and 8 portfolio investments for the quarters ended March 31, June 30, September 30, and December 31, 2010, respectively. The Board of Directors of Main Street has the final responsibility for reviewing and approving, in good faith, Main Street's estimate of the fair value for the investments.

Determination of fair value involves subjective judgments and estimates. The notes to our financial statements will refer to the uncertainty with respect to the possible effect of such valuations, and any change in such valuations, on our financial statements.

We compete for investments with a number of investment funds (including private equity funds, mezzanine funds, BDCs, and other SBICs), as well as traditional financial services companies such as commercial banks and other sources of financing. Many of the entities that compete with us have greater financial and managerial resources. We believe we are able to be competitive with these entities primarily on the basis of our focus toward the underserved lower middle market, the experience and contacts of our

management team, our responsive and efficient investment analysis and decision-making processes, our comprehensive suite of customized financing solutions and the investment terms we offer.

We believe that some of our competitors make senior secured loans, junior secured loans and subordinated debt investments with interest rates and returns that are comparable to or lower than the rates and returns that we target. Therefore, we do not seek to compete primarily on the interest rates and returns that we offer to potential portfolio companies. For additional information concerning the competitive risks we face, see "Risk Factors — We may face increasing competition for investment opportunities."

As of December 31, 2010, we had 18 employees, each of whom was employed by the Investment Manager. These employees include investment and portfolio management professionals, operations professionals and administrative staff. As necessary, we will hire additional investment professionals and administrative personnel. All of our employees are located in our Houston, Texas office.

We have elected to be regulated as a BDC under the 1940 Act. The 1940 Act contains prohibitions and restrictions relating to transactions between BDCs and their affiliates, principal underwriters and affiliates of those affiliates or underwriters. The 1940 Act requires that a majority of the members of the board of directors of a BDC be persons other than "interested persons," as that term is defined in the 1940 Act. In addition, the 1940 Act provides that we may not change the nature of our business so as to cease to be, or to withdraw our election as, a BDC unless approved by a majority of our outstanding voting securities.

The 1940 Act defines "a majority of the outstanding voting securities" as the lesser of (i) 67% or more of the voting securities present at a meeting if the holders of more than 50% of our outstanding voting securities are present or represented by proxy or (ii) more than 50% of our voting securities.

Under the 1940 Act, a BDC may not acquire any asset other than assets of the type listed in Section 55(a) of the 1940 Act, which are referred to as qualifying assets, unless, at the time the acquisition is made, qualifying assets represent at least 70% of the company's total assets. The principal categories of qualifying assets relevant to our business are any of the following:

In addition, a BDC must have been organized and have its principal place of business in the United States and must be operated for the purpose of making investments in the types of securities described in (1), (2) or (3) above.

In order to count portfolio securities as qualifying assets for the purpose of the 70% test, we must either control the issuer of the securities or must offer to make available to the issuer of the securities (other than small and solvent companies described above) significant managerial assistance; except that, where we purchase such securities in conjunction with one or more other persons acting together, one of the other persons in the group may make available such managerial assistance. Making available managerial assistance means, among other things, any arrangement whereby the BDC, through its directors, officers or employees, offers to provide, and, if accepted, does so provide, significant guidance and counsel concerning the management, operations or business objectives and policies of a portfolio company.

Pending investment in "qualifying assets," as described above, our investments may consist of cash, cash equivalents, U.S. government securities, short-term investments in secured debt investments, independently rated debt investments, and diversified bond funds, which we refer to, collectively, as marketable securities and idle funds investments, so that 70% of our assets are qualifying assets.

We are permitted, under specified conditions, to issue multiple classes of debt and one class of stock senior to our common stock if our asset coverage, as defined in the 1940 Act, is at least equal to 200% of all debt and/or senior stock immediately after each such issuance. In addition, while any senior securities remain outstanding (other than senior securities representing indebtedness issued in consideration of a privately arranged loan which is not intended to be publicly distributed), we must make provisions to prohibit any distribution to our stockholders or the repurchase of such securities or shares unless we meet the applicable asset coverage ratios at the time of the distribution or repurchase. We may also borrow amounts up to 5% of the value of our total assets for temporary or emergency purposes without regard to asset coverage. For a

discussion of the risks associated with leverage, see "Risk Factors — Risks Relating to Our Business and Structure," including, without limitation, "— Because we borrow money, the potential for gain or loss on amounts invested in us is magnified and may increase the risk of investing in us."

In January 2008, we received an exemptive order from the SEC to exclude debt securities issued by MSMF from the asset coverage requirements of the 1940 Act as applicable to Main Street. The exemptive order provides for the exclusion of all debt securities issued by MSMF, including the $85 million of currently outstanding debt related to its participation in the SBIC program. This exemptive order provides us with expanded capacity and flexibility in obtaining future sources of capital for our investment and operational objectives. We expect to have similar relief from the SEC with respect to SBIC debt securities issued by MSC II, including the $95 million of currently outstanding debt related to its participation in the SBIC program.

We are not generally able to issue and sell our common stock at a price below net asset value per share. We may, however, sell our common stock, warrants, options or rights to acquire our common stock, at a price below the current net asset value of the common stock if our board of directors determines that such sale is in our best interests and that of our stockholders, and our stockholders approve such sale. In any such case, the price at which our securities are to be issued and sold may not be less than a price which, in the determination of our board of directors, closely approximates the market value of such securities (less any distributing commission or discount). A proposal, approved by our stockholders at our June 2010 annual meeting of stockholders, authorizes us to sell shares of our common stock below the then current net asset value per share of our common stock in one or more offerings for a period of one year ending on June 9, 2011. We would need similar future approval from our stockholders to issue shares below the then current net asset value per share any time after the expiration of the current approval. On June 17, 2008, our stockholders approved another proposal that authorizes us to issue securities to subscribe to, convert to, or purchase shares of our common stock in one or more offerings. We may also make rights offerings to our stockholders at prices per share less than the net asset value per share, subject to applicable requirements of the 1940 Act. See "Risk Factors — Risks Relating to Our Business and Structure — Stockholders may incur dilution if we sell shares of our common stock in one or more offerings at prices below the then current net asset value per share of our common stock or issue securities to subscribe to, convert to or purchase shares of our common stock."

We have adopted a code of ethics pursuant to Rule 17j-1 under the 1940 Act that establishes procedures for personal investments and restricts certain personal securities transactions. Personnel subject to the code may invest in securities for their personal investment accounts, including securities that may be purchased or held by us, so long as such investments are made in accordance with the code's requirements.

We vote proxies relating to our portfolio securities in a manner in which we believe is consistent with the best interest of our stockholders. We review on a case-by-case basis each proposal submitted to a stockholder vote to determine its impact on the portfolio securities held by us. Although we generally vote against proposals that we expect would have a negative impact on our portfolio securities, we may vote for such a proposal if there exists compelling long-term reasons to do so.

Our proxy voting decisions are made by the deal team which is responsible for monitoring each of our investments. To ensure that our vote is not the product of a conflict of interest, we require that: (i) anyone involved in the decision-making process to disclose to our chief compliance officer any potential conflict of which he or she is aware and any contact that he or she has had with any interested party regarding a proxy vote and (ii) employees involved in the decision making process or vote administration are prohibited from revealing how we intend to vote on a proposal in order to reduce any attempted influence from interested parties.

Stockholders may obtain information, without charge, regarding how we voted proxies with respect to our portfolio securities by making a written request for proxy voting information to: Chief Compliance Officer, 1300 Post Oak Boulevard, Suite 800, Houston, Texas 77056.

We may also be prohibited under the 1940 Act from knowingly participating in certain transactions with our affiliates without the prior approval of our Board of Directors who are not interested persons and, in some cases, prior approval by the SEC. In June 2008, we received an exemptive order from the SEC to permit co-investments in portfolio companies among Main Street and certain of its affiliates, including MSC II, subject to certain conditions of the order.

We are required to provide and maintain a bond issued by a reputable fidelity insurance company to protect us against larceny and embezzlement. Furthermore, as a BDC, we are prohibited from protecting any director or officer against any liability to us or our stockholders arising from willful misfeasance, bad faith, gross negligence or reckless disregard of the duties involved in the conduct of such person's office.

We are required to adopt and implement written policies and procedures reasonably designed to prevent violation of the federal securities laws, review these policies and procedures annually for their adequacy and the effectiveness of their implementation, and to designate a chief compliance officer to be responsible for administering the policies and procedures.

Each of the Funds is licensed by the SBA to operate as a SBIC under Section 301(c) of the Small Business Investment Act of 1958. As a part of the Formation Transactions, MSMF became a wholly owned subsidiary of MSCC, and continues to hold its SBIC license. MSMF initially obtained its SBIC license in September 2002. As part of the Exchange Offer Transactions, MSC II became a majority owned subsidiary of MSCC and continues to hold its license. MSC II initially obtained its SBIC license in January 2006.

SBICs are designed to stimulate the flow of private equity capital to eligible small businesses. Under SBIC regulations, SBICs may make loans to eligible small businesses, invest in the equity securities of such businesses and provide them with consulting and advisory services. Each of the Funds has typically invested in secured debt, acquired warrants and/or made equity investments in qualifying small businesses.

Under present SBIC regulations, eligible small businesses generally include businesses that (together with their affiliates) have a tangible net worth not exceeding $18 million and have average annual net income after federal income taxes not exceeding $6 million (average net income to be computed without benefit of any carryover loss) for the two most recent fiscal years. In addition, an SBIC must devote 20% of its investment activity to "smaller" concerns as defined by the SBA. A smaller concern generally includes businesses that have a tangible net worth not exceeding $6 million and have average annual net income after federal income taxes not exceeding $2 million (average net income to be computed without benefit of any net carryover loss) for the two most recent fiscal years. SBIC regulations also provide alternative size standard criteria to determine eligibility for designation as an eligible small business or smaller concern, which criteria depend on the primary industry in which the business is engaged and are based on such factors as the number of employees and gross revenue. However, once an SBIC has invested in a company, it may continue to make

follow on investments in the company, regardless of the size of the portfolio company at the time of the follow on investment, up to the time of the portfolio company's initial public offering.

The SBA prohibits an SBIC from providing funds to small businesses for certain purposes, such as relending and investment outside the United States, to businesses engaged in a few prohibited industries, and to certain "passive" (non-operating) companies. In addition, without prior SBA approval, an SBIC may not invest an amount equal to more than approximately 30% of the SBIC's regulatory capital in any one portfolio company and its affiliates.

The SBA places certain limitations on the financing terms of investments by SBICs in portfolio companies (such as limiting the permissible interest rate on debt securities held by an SBIC in a portfolio company). Although prior regulations prohibited an SBIC from controlling a small business concern except in limited circumstances, regulations adopted by the SBA in 2002 now allow an SBIC to exercise control over a small business for a period of seven years from the date on which the SBIC initially acquires its control position. This control period may be extended for an additional period of time with the SBA's prior written approval.

The SBA restricts the ability of an SBIC to lend money to any of its officers, directors and employees or to invest in affiliates thereof. The SBA also prohibits, without prior SBA approval, a "change of control" of an SBIC or transfers that would result in any person (or a group of persons acting in concert) owning 10% or more of a class of equity for a licensed SBIC. A "change of control" is any event which would result in the transfer of the power, direct or indirect, to direct the management and policies of an SBIC, whether through ownership, contractual arrangements or otherwise.

An SBIC (or group of SBICs under common control) may generally have outstanding debentures guaranteed by the SBA in amounts up to twice the amount of the privately-raised funds of the SBIC(s). Debentures guaranteed by the SBA have a maturity of ten years, require semi-annual payments of interest, do not require any principal payments prior to maturity, and, historically, were subject to certain prepayment penalties. Those prepayment penalties no longer apply as of September 2006. As of December 31, 2010, we, through the Funds, had issued $180 million of SBA-guaranteed debentures, which had an annual weighted average interest rate of approximately 5.2%.

The American Recovery and Reinvestment Act of 2009 enacted in February 2009 (the "Stimulus Bill") contains several provisions applicable to SBIC funds, including the Funds. One of the key SBIC-related provisions included in the Stimulus Bill increased the maximum amount of combined SBIC leverage (or SBIC leverage cap) to $225 million for affiliated SBIC funds. The prior maximum amount of SBIC leverage available to affiliated SBIC funds was approximately $137 million. Since the increase in the SBIC leverage cap applies to affiliated SBIC funds, Main Street is required to allocate such increased borrowing capacity between the Funds. Subsequent to the Exchange Offer, Main Street now has access to a combined incremental $45 million in SBIC leverage capacity, subject to the required capitalization of each of the Funds, in addition to the $180 million of existing SBIC leverage.

SBICs must invest idle funds that are not being used to make loans in investments permitted under SBIC regulations in the following limited types of securities: (i) direct obligations of, or obligations guaranteed as to principal and interest by, the United States government, which mature within 15 months from the date of the investment; (ii) repurchase agreements with federally insured institutions with a maturity of seven days or less (and the securities underlying the repurchase obligations must be direct obligations of or guaranteed by the federal government); (iii) certificates of deposit with a maturity of one year or less, issued by a federally insured institution; (iv) a deposit account in a federally insured institution that is subject to a withdrawal restriction of one year or less; (v) a checking account in a federally insured institution; or (vi) a reasonable petty cash fund.

SBICs are periodically examined and audited by the SBA's staff to determine their compliance with SBIC regulations and are periodically required to file certain financial information and other documents with the SBA.

Neither the SBA nor the U.S. government or any of its agencies or officers has approved any ownership interest to be issued by us or any obligation that we or any of our subsidiaries may incur.

We are subject to the reporting and disclosure requirements of the Securities Exchange Act of 1934 (the "Exchange Act"), including the filing of quarterly, annual and current reports, proxy statements and other required items. In addition, we are subject to the Sarbanes-Oxley Act of 2002, which imposes a wide variety of regulatory requirements on publicly-held companies and their insiders. For example:

The New York Stock Exchange ("NYSE") has adopted corporate governance regulations that listed companies must comply with. We believe we are in compliance with such corporate governance listing standards. We intend to monitor our compliance with all future listing standards and to take all necessary actions to ensure that we stay in compliance.

MSCC has elected to be treated for federal income tax purposes as a regulated investment company ("RIC") under Subchapter M of the Internal Revenue Code (the "Code") commencing October 2, 2007. As a RIC, we generally do not have to pay corporate-level federal income taxes on any income that we distribute to our stockholders as dividends. To qualify as a RIC, we must, among other things, meet certain source-of-income and asset diversification requirements (as described below). In addition, in order to obtain RIC tax treatment, we must distribute to our stockholders, for each taxable year, at least 90% of our "investment company taxable income," which is generally our net ordinary income plus the excess of realized net short-term capital gains over realized net long-term capital losses (the "Annual Distribution Requirement").

For any taxable year in which we qualify as a RIC and satisfy the Annual Distribution Requirement, we will not be subject to federal income tax on the portion of our income we distribute (or are deemed to distribute) to stockholders. We will be subject to U.S. federal income tax at the regular corporate rates on any income or capital gains not distributed (or deemed distributed) to our stockholders.

We will be subject to a 4% nondeductible federal excise tax on certain undistributed income unless we distribute in a timely manner an amount at least equal to the sum of (1) 98% of our net ordinary income for each calendar year, (2) 98% of our capital gain net income for the one-year period ending October 31 in that calendar year and (3) any income recognized, but not distributed, in preceding years (the "Excise Tax Avoidance Requirement"). Dividends declared and paid by us in a year will generally differ from taxable income for that year as such dividends may include the distribution of current year taxable income, less amounts carried over into the following year, and the distribution of prior year taxable income carried over

into and distributed in the current year. For amounts we carry over into the following year, we will be required to pay the 4% excise tax based on 98% of our annual taxable income in excess of distributions for the year.

In order to qualify as a RIC for federal income tax purposes, we must, among other things:

In order to comply with the 90% Income Test, we formed the Taxable Subsidiaries as wholly owned taxable subsidiaries of MSCC and MSC II, for the primary purpose of permitting us to own equity interests in portfolio companies which are "pass through" entities for tax purposes. Absent the taxable status of the Taxable Subsidiaries, a portion of the gross income from such portfolio companies would flow directly to us for purposes of the 90% Income Test. To the extent such income did not consist of income derived from securities, such as dividends and interest, it could jeopardize our ability to qualify as a RIC and, therefore cause us to incur significant federal income taxes. The Taxable Subsidiaries are consolidated with Main Street for GAAP purposes, and the portfolio investments held by the Taxable Subsidiaries are included in our consolidated financial statements. The Taxable Subsidiaries are not consolidated with Main Street for income tax purposes and may generate income tax expense as a result of their ownership of the portfolio investments. This income tax expense, if any, is reflected in our Consolidated Statement of Operations.

We may be required to recognize taxable income in circumstances in which we do not receive cash. For example, if we hold debt obligations that are treated under applicable tax rules as having original issue discount (such as debt instruments issued with warrants), we must include in income each year a portion of the original issue discount that accrues over the life of the obligation, regardless of whether cash representing such income is received by us in the same taxable year. We may also have to include in income other amounts that we have not yet received in cash, such as PIK interest and deferred loan origination fees that are paid after origination of the loan or are paid in non-cash compensation such as warrants or stock. Because any original issue discount or other amounts accrued will be included in our investment company taxable income for the year of accrual, we may be required to make a distribution to our stockholders in order to satisfy the Annual Distribution Requirement, even though we will not have received any corresponding cash amount.

Although we do not presently expect to do so, we are authorized to borrow funds and to sell assets in order to satisfy distribution requirements. However, under the 1940 Act, we are not permitted to make distributions to our stockholders in certain circumstances while our debt obligations and other senior securities are outstanding unless certain "asset coverage" tests are met. See "— Regulation — Regulation as a Business Development Company — Senior Securities." Moreover, our ability to dispose of assets to meet our distribution requirements may be limited by (1) the illiquid nature of our portfolio and/or (2) other requirements relating to our status as a RIC, including the Diversification Tests. If we dispose of assets in order to meet the Annual Distribution Requirement or the Excise Tax Avoidance Requirement, we may make such dispositions at times that, from an investment standpoint, are not advantageous.

Pursuant to a revenue procedure issued by the Internal Revenue Service, or the IRS, the IRS has indicated that it will treat distributions from certain publicly traded RICs (including business development companies) that are paid part in cash and part in stock as dividends that would satisfy the RIC's annual distribution requirements. In order to qualify for such treatment, the revenue procedure requires that at least 10% of the total distribution be paid in cash and that each stockholder have a right to elect to receive its entire distribution in cash. If too many stockholders elect to receive cash, each stockholder electing to receive cash must receive a proportionate share of the cash to be distributed (although no stockholder electing to receive cash may receive less than 10% of such stockholder's distribution in cash). This revenue procedure applies to distributions declared on or before December 31, 2012, with respect to taxable years ended on or before December 31, 2011.

We are also subject to regulation under the Investment Advisers Act of 1940, as amended (the "Advisers Act"). The Advisers Act establishes, among other things, recordkeeping and reporting requirements, disclosure requirements, limitations on transactions between the adviser's account and an advisory client's account, limitations on transactions between the accounts of advisory clients, and general anti-fraud prohibitions. We will also be examined by the SEC from time to time for compliance with the Advisers Act.

Investing in our common stock involves a number of significant risks. In addition to the other information contained in this Annual Report on Form 10-K, investors should consider carefully the following information before making an investment in our common stock. The risks set out below are not the only risks we face. Additional risks and uncertainties not presently known to us or not presently deemed material by us might also impair our operations and performance. If any of the following events occur, our business, financial condition and results of operations could be materially and adversely affected.

The broader economic fundamentals of the United States economy remain at relatively depressed levels. Unemployment levels remain elevated and consumer fundamentals remain depressed, which has led to significant reductions in spending by both consumers and businesses. In the event that the United States economy remains depressed, it is likely that the financial results of small- to mid-sized companies, like those in which we invest, could experience deterioration or limited growth from current levels, which could ultimately lead to difficulty in meeting their debt service requirements and an increase in defaults. In addition, the end markets for certain of our portfolio companies' products and services have experienced negative economic trends. We have seen reduced operating results at several portfolio companies due to the general economic difficulties, and the trend of reduced operating results may continue into 2011.

Consequently, we can provide no assurance that the performance of certain of our portfolio companies will not be negatively impacted by these economic or other conditions, which could also have a negative impact on our future results.

Although we have been able to secure access to additional liquidity, including our $100 million investment credit facility and the increase in available leverage through the SBIC program as part of the 2009 Stimulus Bill, the current uncertainty in the debt and in the equity capital markets provides no assurance that debt or equity capital will be available to us in the future on favorable terms, or at all.

Under the 1940 Act, we are required to carry our portfolio investments at market value or, if there is no readily available market value, at fair value as determined by us with our Board of Directors having final responsibility for overseeing, reviewing and approving, in good faith, our estimate of fair value. Typically, there is not a public market for the securities of the privately held companies in which we have invested and will generally continue to invest. As a result, we value these securities quarterly at fair value based on inputs from management, a third party independent valuation firm and our audit committee and with the oversight, review and approval of our Board of Directors.

The determination of fair value and consequently, the amount of unrealized gains and losses in our portfolio, are to a certain degree, subjective and dependent on a valuation process approved by our Board of Directors. Certain factors that may be considered in determining the fair value of our investments include external events, such as private mergers, sales and acquisitions involving comparable companies. Because such valuations, and particularly valuations of private securities and private companies, are inherently uncertain, may fluctuate over short periods of time and may be based on estimates, our determinations of fair value may differ materially from the values that would have been used if a ready market for these securities existed. Due to this uncertainty, our fair value determinations may cause our net asset value on a given date to materially understate or overstate the value that we may ultimately realize on one or more of our investments. As a result, investors purchasing our common stock based on an overstated net asset value would pay a higher price than the value of our investments might warrant. Conversely, investors selling shares during a period in which the net asset value understates the value of our investments will receive a lower price for their shares than the value of our investments might warrant.

Our ability to achieve our investment objective of maximizing our portfolio's total return by generating current income from our debt investments and capital appreciation from our equity and equity-related investments, including warrants, convertible securities and other rights to acquire equity securities in a portfolio company, depends on our ability to effectively manage and deploy capital, which depends, in turn, on our investment team's ability to identify, evaluate and monitor, and our ability to finance and invest in, companies that meet our investment criteria.

Accomplishing our investment objective on a cost-effective basis is largely a function of our investment team's handling of the investment process, its ability to provide competent, attentive and efficient services and our access to investments offering acceptable terms. In addition to monitoring the performance of our existing investments, members of our investment team are also called upon, from time to time, to provide managerial assistance to some of our portfolio companies. These demands on their time may distract them or slow the rate of investment.

Even if we are able to grow and build upon our investment operations, any failure to manage our growth effectively could have a material adverse effect on our business, financial condition, results of operations and prospects. The results of our operations will depend on many factors, including the availability of opportunities for investment, readily accessible short and long-term funding alternatives in the financial markets and economic conditions. Furthermore, if we cannot successfully operate our business or implement our investment policies and strategies as described herein, it could negatively impact our ability to pay dividends.

We compete for investments with other investment funds (including private equity funds, mezzanine funds, BDCs, and other SBICs), as well as traditional financial services companies such as commercial banks and other sources of funding. Many of our competitors are substantially larger and have considerably greater financial, technical and marketing resources than we do. For example, some competitors may have a lower cost of capital and access to funding sources that are not available to us, including from federal government agencies. In addition, some of our competitors may have higher risk tolerances or different risk assessments than we have. These characteristics could allow our competitors to consider a wider variety of investments, establish more relationships and offer better pricing and more flexible structuring than we are able to do. We may lose investment opportunities if we do not match our competitors' pricing, terms and structure. If we are forced to match our competitors' pricing, terms and structure, we may not be able to achieve acceptable returns on our investments or may bear substantial risk of capital loss. A significant part of our competitive advantage stems from the fact that the market for investments in LMM companies is underserved by traditional commercial banks and other financing sources. A significant increase in the number and/or the size of our competitors in this target market could force us to accept less attractive investment terms. Furthermore, many of our competitors have greater experience operating under, or are not subject to, the regulatory restrictions that the 1940 Act imposes on us as a BDC.

We depend on the members of our investment team, particularly Vincent D. Foster, Todd A. Reppert, Rodger A. Stout, Curtis L. Hartman, Dwayne L. Hyzak and David L. Magdol, for the identification, review, final selection, structuring, closing and monitoring of our investments. These employees have significant investment expertise and relationships that we rely on to implement our business plan. Although we have entered into a non-compete agreement with Mr. Foster, we have no guarantee that he or any other employees will remain employed with us. If we lose the services of these individuals, we may not be able to operate our business as we expect, and our ability to compete could be harmed, which could cause our operating results to suffer.

Our growth will require that we retain new investment and administrative personnel in a competitive market. Our ability to attract and retain personnel with the requisite credentials, experience and skills depends on several factors including, but not limited to, our ability to offer competitive wages, benefits and professional growth opportunities. Many of the entities, including investment funds (such as private equity funds and mezzanine funds) and traditional financial services companies, with which we compete for experienced personnel have greater resources than we have.

The competitive environment for qualified personnel may require us to take certain measures to ensure that we are able to attract and retain experienced personnel. Such measures may include increasing the attractiveness of our overall compensation packages, altering the structure of our compensation packages through the use of additional forms of compensation, or other steps. The inability to attract and retain experienced personnel would have a material adverse effect on our business.

We expect that members of our management team will maintain their relationships with intermediaries, financial institutions, investment bankers, commercial bankers, financial advisors, attorneys, accountants, consultants and other individuals within our network, and we will rely to a significant extent upon these relationships to provide us with potential investment opportunities. If our management team fails to maintain its existing relationships or develop new relationships with sources of investment opportunities, we will not be able to grow our investment portfolio. In addition, individuals with whom members of our management team have relationships are not obligated to provide us with investment opportunities, and, therefore, there is no assurance that such relationships will generate investment opportunities for us.

The 1940 Act imposes numerous constraints on the operations of BDCs. Prior to the completion of the IPO, we did not operate, and our management team had no experience operating, as a BDC under the 1940 Act or as a RIC under Subchapter M of the Code. As a result, we have limited operating results under these regulatory frameworks that can demonstrate either their effect on our business or our ability to manage our business under these frameworks. Our management team's limited experience in managing a portfolio of assets under such constraints may hinder our ability to take advantage of attractive investment opportunities and, as a result, achieve our investment objective. Furthermore, any failure to comply with the requirements imposed on BDCs by the 1940 Act could cause the SEC to bring an enforcement action against us. If we do not remain a BDC, we might be regulated as a registered closed-end investment company under the 1940 Act, which would further decrease our operating flexibility.

Our business will require capital to operate and grow. We may acquire such additional capital from the following sources:

Senior Securities. We may issue debt securities or preferred stock and/or borrow money from banks or other financial institutions, which we refer to collectively as senior securities. As a result of issuing senior securities, we will be exposed to additional risks, including the following:

Additional Common Stock. We are not generally able to issue and sell our common stock at a price below net asset value per share. We may, however, sell our common stock, warrants, options or rights to acquire our common stock, at a price below the current net asset value of the common stock if our Board of Directors determines that such sale is in the best interests of our stockholders, and our stockholders approve such sale. See "— Stockholders may incur dilution if we sell shares of our common stock in one or more offerings at prices below the then current net asset value per share of our common stock or issue securities to subscribe to, convert to or purchase shares of our common stock" for a discussion of proposals approved by our stockholders that permit us to issue shares of our common stock below net asset value. We may also make rights offerings to our stockholders at prices per share less than the net asset value per share, subject to applicable requirements of the 1940 Act. If we raise additional funds by issuing more common stock or senior securities convertible into, or exchangeable for, our common stock, the percentage ownership of our stockholders at that time would decrease, and they may experience dilution. Moreover, we can offer no assurance that we will be able to issue and sell additional equity securities in the future, on favorable terms or at all.

MSMF, our wholly owned subsidiary, and MSC II, our majority-owned subsidiary, are licensed to act as small business investment companies and are regulated by the SBA. The SBA also places certain limitations on the financing terms of investments by SBICs in portfolio companies and prohibits SBICs from providing funds for certain purposes or to businesses in a few prohibited industries. Compliance with SBA requirements may cause the Funds to forego attractive investment opportunities that are not permitted under SBA regulations.

Further, the SBA regulations require that a licensed SBIC be periodically examined and audited by the SBA to determine its compliance with the relevant SBA regulations. The SBA prohibits, without prior SBA approval, a "change of control" of an SBIC or transfers that would result in any person (or a group of persons acting in concert) owning 10% or more of a class of capital stock of a licensed SBIC. If the Funds fail to comply with applicable SBIC regulations, the SBA could, depending on the severity of the violation, limit or prohibit its use of debentures, declare outstanding debentures immediately due and payable, and/or limit it from making new investments. In addition, the SBA can revoke or suspend a license for willful or repeated violation of, or willful or repeated failure to observe, any provision of the Small Business Investment Act of 1958 or any rule or regulation promulgated thereunder. Such actions by the SBA would, in turn, negatively affect us.

Borrowings, also known as leverage, magnify the potential for gain or loss on invested equity capital. As we use leverage to partially finance our investments, you will experience increased risks of investing in our common stock. We, through the Funds, issue debt securities guaranteed by the SBA and sold in the capital markets. As a result of its guarantee of the debt securities, the SBA has fixed dollar claims on the assets of the Funds that are superior to the claims of our common stockholders. We may also borrow from banks and other lenders, including under the $85 million investment credit facility we entered into during 2010 and expanded to $100 million during January 2011. See "Management's Discussion and Analysis of Financial Condition and Results of Operations — Capital Resources" for a discussion regarding our investment credit facility. If the value of our assets increases, then leveraging would cause the net asset value attributable to our common stock to increase more sharply than it would have had we not leveraged. Conversely, if the value of our assets decreases, leveraging would cause net asset value to decline more sharply than it otherwise would have had we not leveraged our business. Similarly, any increase in our income in excess of interest payable on the borrowed funds would cause our net investment income to increase more than it would without the

leverage, while any decrease in our income would cause net investment income to decline more sharply than it would have had we not borrowed. Such a decline could negatively affect our ability to pay common stock dividends. Leverage is generally considered a speculative investment technique.

As of December 31, 2010, we, through the Funds, had $180 million of outstanding indebtedness guaranteed by the SBA, which had a weighted average annualized interest cost of approximately 5.2% (exclusive of deferred financing costs). The debentures guaranteed by the SBA have a maturity of ten years and require semi-annual payments of interest. We will need to generate sufficient cash flow to make required interest payments on the debentures. If we are unable to meet the financial obligations under the debentures, the SBA, as a creditor, will have a superior claim to the assets of the Funds over our stockholders in the event we liquidate or the SBA exercises its remedies under such debentures as the result of a default by us. In addition, as of December 31, 2010, we had $39 million outstanding under the Credit Facility. Borrowings under the Credit Facility bear interest, subject to our election, on a per annum basis equal to (i) the applicable LIBOR rate plus 2.50% or (ii) the applicable base rate plus 1.50%. Main Street pays unused commitment fees of 0.375% per annum on the average unused lender commitments under the Credit Facility. If we are unable to meet the financial obligations under the Credit Facility, the Credit Facility lending group will have a superior claim to the assets of MSCC and its subsidiaries (excluding the assets of the Funds) over our stockholders in the event we liquidate or the lending group exercises its remedies under the Credit Facility as the result of a default by us.

Illustration. The following table illustrates the effect of leverage on returns from an investment in our common stock assuming various annual returns, net of expenses. The calculations in the table below are hypothetical and actual returns may be higher or lower than those appearing below.

Our ability to achieve our investment objective may depend in part on our ability to access additional leverage on favorable terms by issuing debentures guaranteed by the SBA, through the Funds, or by borrowing from banks or insurance companies, and there can be no assurance that such additional leverage can in fact be achieved.

We could experience fluctuations in our quarterly operating results due to a number of factors, including our ability or inability to make investments in companies that meet our investment criteria, the interest rate payable on the debt securities we acquire, the level of portfolio dividend and fee income, the level of our expenses, variations in and the timing of the recognition of realized and unrealized gains or losses, the degree to which we encounter competition in our markets and general economic conditions. As a result of these factors, results for any period should not be relied upon as being indicative of performance in future periods.

Our Board of Directors has the authority to modify or waive our current operating policies, investment criteria and strategies without prior notice and without stockholder approval. We cannot predict the effect any changes to our current operating policies, investment criteria and strategies would have on our business, net

asset value, operating results and value of our stock. However, the effects might be adverse, which could negatively impact our ability to pay you dividends and cause you to lose all or part of your investment.

To maintain RIC tax treatment under the Code, we must meet the following annual distribution, income source and asset diversification requirements:

Failure to meet these requirements may result in our having to dispose of certain investments quickly in order to prevent the loss of RIC status. Because most of our investments will be in private companies, and therefore will be relatively illiquid, any such dispositions could be made at disadvantageous prices and could result in substantial losses. Moreover, if we fail to maintain RIC tax treatment for any reason and are subject to corporate income tax, the resulting corporate taxes could substantially reduce our net assets, the amount of income available for distribution and the amount of our distributions.

We intend to pay monthly dividends to our stockholders out of assets legally available for distribution. We cannot assure you that we will achieve investment results that will allow us to pay a specified level of cash dividends, previously projected dividends for future periods, or year-to-year increases in cash dividends. Our ability to pay dividends might be adversely affected by, among other things, the impact of one or more of the risk factors described herein. In addition, the inability to satisfy the asset coverage test applicable to us as a BDC could limit our ability to pay dividends. All dividends will be paid at the discretion of our Board of Directors and will depend on our earnings, our financial condition, maintenance of our RIC status, compliance with applicable BDC regulations, each of the Funds' compliance with applicable SBIC regulations and such other factors as our Board of Directors may deem relevant from time to time. We cannot assure you that we will pay dividends to our stockholders in the future.

When we make monthly distributions, we will be required to determine the extent to which such distributions are paid out of current or accumulated earnings, recognized capital gains or capital. To the extent there is a return of capital, investors will be required to reduce their basis in our stock for federal tax purposes. In the future, our distributions may include a return of capital.

For federal income tax purposes, we will include in income certain amounts that we have not yet received in cash, such as original issue discount, which may arise if we receive warrants in connection with the origination of a loan or possibly in other circumstances, or contractual payment-in-kind, or PIK, interest, which represents contractual interest added to the loan balance and due at the end of the loan term. Such original issue discounts or increases in loan balances as a result of contractual PIK arrangements will be included in income before we receive any corresponding cash payments. We also may be required to include in income certain other amounts that we will not receive in cash. Approximately 6.4% of our total investment income for the year ended December 31, 2010 was attributable to paid in kind interest.

Since, in certain cases, we may recognize income before or without receiving cash representing such income, we may have difficulty meeting the annual distribution requirement necessary to maintain RIC tax treatment under the Code. Accordingly, we may have to sell some of our investments at times and/or at prices we would not consider advantageous, raise additional debt or equity capital or forgo new investment opportunities for this purpose. If we are not able to obtain cash from other sources, we may fail to qualify for RIC tax treatment and thus become subject to corporate-level income tax. For additional discussion regarding the tax implications of a RIC, please see "Business — Regulation — Taxation as a Regulated Investment Company."

We may distribute taxable dividends that are payable in part in our stock. Under an IRS revenue procedure, up to 90% of any such taxable dividend declared on or before December 31, 2012 with respect to taxable years ended on or before December 31, 2011 could be payable in our stock. Where the IRS revenue procedure is not currently applicable, the IRS has also issued private letter rulings on cash and stock dividends paid by RICs and real estate investment trusts using a 20% cash standard (and, more recently, the 10% cash standard of the above-referenced IRS revenue procedure) if certain requirements are satisfied. Taxable stockholders receiving such dividends will be required to include the full amount of the dividend as ordinary income (or as long-term capital gain to the extent such distribution is properly designated as a capital gain dividend) to the extent of our current and accumulated earnings and profits for United States federal income tax purposes. As a result, a U.S. stockholder may be required to pay tax with respect to such dividends in excess of any cash received. If a U.S. stockholder sells the stock it receives as a dividend in order to pay this tax, the sales proceeds may be less than the amount included in income with respect to the dividend, depending on the market price of our stock at the time of the sale. Furthermore, with respect to non-U.S. stockholders, we may be required to withhold U.S. tax with respect to such dividends, including in respect of all or a portion of such dividend that is payable in stock. In addition, if a significant number of our stockholders determine to sell shares of our stock in order to pay taxes owed on dividends, it may put downward pressure on the trading price of our stock.

In order for us to continue to qualify for RIC tax treatment and to minimize corporate-level taxes, we will be required to distribute substantially all of our net ordinary income and net capital gain income, including income from certain of our subsidiaries, which includes the income from the Funds. We will be partially dependent on the Funds for cash distributions to enable us to meet the RIC distribution

requirements. The Funds may be limited by the Small Business Investment Act of 1958, and SBIC regulations governing SBICs, from making certain distributions to us that may be necessary to enable us to maintain our status as a RIC. We may have to request a waiver of the SBA's restrictions for the Funds to make certain distributions to maintain our eligibility for RIC status. We cannot assure you that the SBA will grant such waiver and if the Funds are unable to obtain a waiver, compliance with the SBIC regulations may result in loss of RIC tax treatment and a consequent imposition of an entity-level tax on us.

In order to satisfy the requirements applicable to a RIC and to minimize corporate-level taxes, we intend to distribute to our stockholders substantially all of our net ordinary income and net capital gain income. We may carry forward excess undistributed taxable income into the next year, net of the 4% excise tax. Any such carryover taxable income must be distributed through a dividend declared prior to filing the final tax return related to the year which generated such taxable income. As a BDC, we generally are required to meet an asset coverage ratio, as defined in the 1940 Act, of at least 200% immediately after each issuance of senior securities. This requirement limits the amount that we may borrow. Because we will continue to need capital to grow our investment portfolio, this limitation may prevent us from incurring debt and require us to raise additional equity at a time when it may be disadvantageous to do so.

While we expect to be able to borrow and to issue additional debt and equity securities, we cannot assure you that debt and equity financing will be available to us on favorable terms, or at all. In addition, as a BDC, we generally are not permitted to issue equity securities priced below net asset value without stockholder approval. If additional funds are not available to us, we could be forced to curtail or cease new investment activities, and our net asset value could decline.

The 1940 Act prohibits us from selling shares of our common stock at a price below the current net asset value per share of such stock, with certain exceptions. One such exception is prior stockholder approval of issuances below net asset value provided that our Board of Directors makes certain determinations. At our 2010 annual meeting of stockholders, our stockholders approved a proposal that authorizes us to sell shares of our common stock below the then current net asset value per share of our common stock in one or more offerings for a period of one year ending on the earlier of June 11, 2011 or the date of our 2011 annual meeting of stockholders. Continued access to this exception will require approval of similar proposals at future stockholder meetings. At our 2009 annual meeting of stockholders, our stockholders also approved a proposal to authorize us to issue securities to subscribe to, convert to, or purchase shares of our common stock in one or more offerings. Any decision to sell shares of our common stock below the then current net asset value per share of our common stock or securities to subscribe to, convert to, or purchase shares of our common stock would be subject to the determination by our Board of Directors that such issuance is in our and our stockholders' best interests.

If we were to sell shares of our common stock below net asset value per share, such sales would result in an immediate dilution to the net asset value per share. This dilution would occur as a result of the sale of shares at a price below the then current net asset value per share of our common stock and a proportionately greater decrease in a stockholder's interest in our earnings and assets and voting interest in us than the increase in our assets resulting from such issuance. In addition, if we issue securities to subscribe to, convert to or purchase shares of common stock, the exercise or conversion of such securities would increase the number of outstanding shares of our common stock. Any such exercise would be dilutive on the voting power

of existing stockholders, and could be dilutive with regard to dividends and our net asset value, and other economic aspects of the common stock.

Because the number of shares of common stock that could be so issued and the timing of any issuance is not currently known, the actual dilutive effect cannot be predicted; however, the example below illustrates the effect of dilution to existing stockholders resulting from the sale of common stock at prices below the net asset value of such shares.

Illustration: Example of Dilutive Effect of the Issuance of Shares Below Net Asset Value. Assume that Company XYZ has 1,000,000 total shares outstanding, $15,000,000 in total assets and $5,000,000 in total liabilities. The net asset value per share of the common stock of Company XYZ is $10.00. The following table illustrates the reduction to net asset value, or NAV, and the dilution experienced by Stockholder A following the sale of 40,000 shares of the common stock of Company XYZ at $9.50 per share, a price below its NAV per share.

We, the Funds, and our portfolio companies are subject to applicable local, state and federal laws and regulations, including, without limitation, federal immigration laws and regulations. New legislation may be enacted or new interpretations, rulings or regulations could be adopted, including those governing the types of investments we are permitted to make, any of which could harm us and our stockholders, potentially with retroactive effect. In addition, any change to the SBA's current debenture SBIC program could have a significant impact on our ability to obtain lower-cost leverage, through the Funds, and therefore, our ability to compete with other finance companies.

Additionally, any changes to the laws and regulations governing our operations relating to permitted investments may cause us to alter our investment strategy in order to avail ourselves of new or different opportunities. Such changes could result in material differences to the strategies and plans set forth herein and may result in our investment focus shifting from the areas of expertise of our investment team to other types of investments in which our investment team may have less expertise or little or no experience. Thus, any such changes, if they occur, could have a material adverse effect on our results of operations and the value of your investment.

Terrorist acts, acts of war or natural disasters may disrupt our operations, as well as the operations of the businesses in which we invest. Such acts have created, and continue to create, economic and political uncertainties and have contributed to global economic instability. Future terrorist activities, military or security operations, or natural disasters could further weaken the domestic/global economies and create additional uncertainties, which may negatively impact the businesses in which we invest directly or indirectly and, in turn, could have a material adverse impact on our business, operating results and financial condition. Losses from terrorist attacks and natural disasters are generally uninsurable.

Investing in our portfolio companies involves a number of significant risks. Among other things, these companies:

In addition, in the course of providing significant managerial assistance to certain of our portfolio companies, certain of our officers and directors may serve as directors on the boards of such companies. To the extent that litigation arises out of our investments in these companies, our officers and directors may be named as defendants in such litigation, which could result in an expenditure of funds (through our indemnification of such officers and directors) and the diversion of management time and resources.

We invest, and will continue to invest in companies whose securities are not publicly traded, and whose securities will be subject to legal and other restrictions on resale or will otherwise be less liquid than publicly traded securities. The illiquidity of these investments may make it difficult for us to sell these investments when desired. In addition, if we are required to liquidate all or a portion of our portfolio quickly, we may

realize significantly less than the value at which we had previously recorded these investments. As a result, we do not expect to achieve liquidity in our investments in the near-term. Our investments are usually subject to contractual or legal restrictions on resale or are otherwise illiquid because there is usually no established trading market for such investments. The illiquidity of most of our investments may make it difficult for us to dispose of them at a favorable price, and, as a result, we may suffer losses.

We may not have the funds or ability to make additional investments in our portfolio companies. After our initial investment in a portfolio company, we may be called upon from time to time to provide additional funds to such company or have the opportunity to increase our investment through the exercise of a warrant to purchase common stock. There is no assurance that we will make, or will have sufficient funds to make, follow-on investments. Any decisions not to make a follow-on investment or any inability on our part to make such an investment may have a negative impact on a portfolio company in need of such an investment, may result in a missed opportunity for us to increase our participation in a successful operation or may reduce the expected yield on the investment.

We invest primarily in secured term debt as well as equity issued by LMM and middle market companies. Our portfolio companies may have, or may be permitted to incur, other debt that ranks equally with, or senior to, the debt in which we invest. By their terms, such debt instruments may entitle the holders to receive payment of interest or principal on or before the dates on which we are entitled to receive payments with respect to the debt instruments in which we invest. Also, in the event of insolvency, liquidation, dissolution, reorganization or bankruptcy of a portfolio company, holders of debt instruments ranking senior to our investment in that portfolio company would typically be entitled to receive payment in full before we receive any distribution. After repaying such senior creditors, such portfolio company may not have any remaining assets to use for repaying its obligation to us. In the case of debt ranking equally with debt instruments in which we invest, we would have to share on an equal basis any distributions with other creditors holding such debt in the event of an insolvency, liquidation, dissolution, reorganization or bankruptcy of the relevant portfolio company.

Even though we may have structured certain of our investments as secured loans, if one of our portfolio companies were to go bankrupt, depending on the facts and circumstances, and based upon principles of equitable subordination as defined by existing case law, a bankruptcy court could subordinate all or a portion of our claim to that of other creditors and transfer any lien securing such subordinated claim to the bankruptcy estate. The principles of equitable subordination defined by case law have generally indicated that a claim may be subordinated only if its holder is guilty of misconduct or where the senior loan is re-characterized as an equity investment and the senior lender has actually provided significant managerial assistance to the bankrupt debtor. We may also be subject to lender liability claims for actions taken by us with respect to a borrower's business or instances where we exercise control over the borrower. It is possible that we could become subject to a lender's liability claim, including as a result of actions taken in rendering significant managerial assistance or actions to compel and collect payments from the borrower outside the ordinary course of business.

Certain loans that we make are secured by a second priority security interest in the same collateral pledged by a portfolio company to secure senior debt owed by the portfolio company to commercial banks or other traditional lenders. Often the senior lender has procured covenants from the portfolio company prohibiting the incurrence of additional secured debt without the senior lender's consent. Prior to and as a condition of permitting the portfolio company to borrow money from us secured by the same collateral pledged to the senior lender, the senior lender will require assurances that it will control the disposition of any collateral in the event of bankruptcy or other default. In many such cases, the senior lender will require us to enter into an "intercreditor agreement" prior to permitting the portfolio company to borrow from us. Typically the intercreditor agreements we are requested to execute expressly subordinate our debt instruments to those held by the senior lender and further provide that the senior lender shall control: (1) the commencement of foreclosure or other proceedings to liquidate and collect on the collateral; (2) the nature, timing and conduct of foreclosure or other collection proceedings; (3) the amendment of any collateral document; (4) the release of the security interests in respect of any collateral; and (5) the waiver of defaults under any security agreement. Because of the control we may cede to senior lenders under intercreditor agreements we may enter, we may be unable to realize the proceeds of any collateral securing some of our loans.

Finally, the value of the collateral securing our debt investment will ultimately depend on market and economic conditions, the availability of buyers and other factors. Therefore, there can be no assurance that the proceeds, if any, from the sale or sales of all of the collateral would be sufficient to satisfy the loan obligations secured by our first or second priority liens. There is also a risk that such collateral securing our investments will decrease in value over time, will be difficult to sell in a timely manner, will be difficult to appraise and will fluctuate in value based upon the success of the portfolio company and market conditions. If such proceeds are not sufficient to repay amounts outstanding under the loan obligations secured by our second priority liens, then we, to the extent not repaid from the proceeds of the sale of the collateral, will only have an unsecured claim against the company's remaining assets, if any.

We are classified as a non-diversified investment company within the meaning of the 1940 Act, which means that we are not limited by the 1940 Act with respect to the proportion of our assets that we may invest in securities of a single issuer. Although we seek to maintain a diversified portfolio in accordance with our business strategies, to the extent that we assume large positions in the securities of a small number of issuers, our net asset value may fluctuate to a greater extent than that of a diversified investment company as a result of changes in the financial condition or the market's assessment of the issuer. We may also be more susceptible to any single economic or regulatory occurrence than a diversified investment company. Beyond our RIC asset diversification requirements, we do not have fixed guidelines for diversification, and our investments could be concentrated in relatively few portfolio companies.

We do not, and do not expect to, control the decision making in many of our portfolio companies, even though we may have board representation or board observation rights, and our debt agreements may contain certain restrictive covenants. As a result, we are subject to the risk that a portfolio company in which we invest will make business decisions with which we disagree and the management of such company, as representatives of the holders of their common equity, will take risks or otherwise act in ways that do not serve our interests as debt investors. Due to the lack of liquidity for our investments in non-traded companies, we may not be able to dispose of our interests in our portfolio companies as readily as we would like or at an

appropriate valuation. As a result, a portfolio company may make decisions that would decrease the value of our portfolio holdings.

A portfolio company's failure to satisfy financial or operating covenants imposed by us or other lenders could lead to non-payment of interest and other defaults and, potentially, termination of its loans and foreclosure on its secured assets, which could trigger cross-defaults under other agreements and jeopardize a portfolio company's ability to meet its obligations under the debt or equity securities that we hold. We may incur expenses to the extent necessary to seek recovery upon default or to negotiate new terms, which may include the waiver of certain financial covenants, with a defaulting portfolio company.

As a BDC, we are required to carry our investments at market value or, if no market value is ascertainable, at the fair value as determined in good faith by our Board of Directors. Decreases in the market values or fair values of our investments will be recorded as unrealized depreciation. Any unrealized losses in our loan portfolio could be an indication of a portfolio company's inability to meet its repayment obligations to us with respect to the affected loans. This could result in realized losses in the future and ultimately in reductions of our income available for distribution in future periods.

We are subject to the risk that the investments we make in our portfolio companies may be repaid prior to maturity. When this occurs, we will generally reinvest these proceeds in temporary investments, pending their future investment in new portfolio companies. These temporary investments will typically have substantially lower yields than the debt being prepaid and we could experience significant delays in reinvesting these amounts. Any future investment in a new portfolio company may also be at lower yields than the debt that was repaid. As a result, our results of operations could be materially adversely affected if one or more of our portfolio companies elect to prepay amounts owed to us. Additionally, prepayments could negatively impact our return on equity, which could result in a decline in the market price of our common stock.

Some of our debt investments will bear interest at variable rates and the interest income from these investments could be negatively affected by decreases in market interest rates. In addition, an increase in interest rates would make it more expensive to use debt to finance our investments. As a result, a significant increase in market interest rates could increase our cost of capital, which would reduce our net investment income. Also, an increase in interest rates available to investors could make an investment in our common stock less attractive if we are not able to increase our dividend rate, a situation which could reduce the value of our common stock. Conversely, a decrease in interest rates may have an adverse impact on our returns by requiring us to seek lower yields on our debt investments and by increasing the risk that our portfolio companies will prepay our debt investments, resulting in the need to redeploy capital at potentially lower rates. A decrease in market interest rates may also adversely impact our returns on idle funds, which would reduce our net investment income.

Certain investments that we have made in the past and may make in the future include warrants or other equity securities. Investments in equity securities involve a number of significant risks, including the risk of further dilution as a result of additional issuances, inability to access additional capital and failure to pay

current distributions. Investments in preferred securities involve special risks, such as the risk of deferred distributions, credit risk, illiquidity and limited voting rights. In addition, we may from time to time make non-control, equity investments in portfolio companies. Our goal is ultimately to realize gains upon our disposition of such equity interests. However, the equity interests we receive may not appreciate in value and, in fact, may decline in value. Accordingly, we may not be able to realize gains from our equity interests, and any gains that we do realize on the disposition of any equity interests may not be sufficient to offset any other losses we experience. We also may be unable to realize any value if a portfolio company does not have a liquidity event, such as a sale of the business, recapitalization or public offering, which would allow us to sell the underlying equity interests. We often seek puts or similar rights to give us the right to sell our equity securities back to the portfolio company issuer. We may be unable to exercise these puts rights for the consideration provided in our investment documents if the issuer is in financial distress.

Marketable securities and idle funds investments can include, among other things, secured and unsecured debt investments, independently rated debt investments and diversified bond funds. Many of these investments in debt obligations are, or would be if rated, below investment grade quality. Indebtedness of below investment grade quality is regarded as having predominantly speculative characteristics with respect to the issuer's capacity to pay interest and repay principal, similar to our portfolio investments in the lower middle market. (See "— Our investments in portfolio companies involve higher levels of risk, and we could lose all or part of our investment.") Many of these marketable securities and idle funds investments are purchased through over the counter or other markets and are therefore liquid at the time of purchase but may subsequently become illiquid due to events relating to the issuer of the securities, market events, economic conditions or investor perceptions. See "— Risks Related to Our Investments — The lack of liquidity in our investments may adversely affect our business" for a description of risks related to holding illiquid investments. In addition, domestic and foreign markets are complex and interrelated, so that events in one sector of the world markets or economy, or in one geographical region, can reverberate and have materially negative consequences for other market, economic or regional sectors in a manner that may not be foreseen and which may materially affect the market price of our marketable securities and idle funds investments. Other risks that our portfolio investments are subject to are also applicable to these marketable securities and idle funds investments. See "— Risks Related to Our Investments" for risks affecting our portfolio investments.

Shares of closed-end investment companies, including BDCs, may trade at a discount to net asset value. This characteristic of closed-end investment companies and BDCs is separate and distinct from the risk that our net asset value per share may decline. We cannot predict whether our common stock will trade at, above or below net asset value. In addition, if our common stock trades below net asset value, we will generally not be able to issue additional common stock at the market price unless our stockholders approve such a sale and our Board of Directors makes certain determinations. See "— Risks Relating to Our Business and Structure — Stockholders may incur dilution if we sell shares of our common stock in one or more offerings at prices below the then current net asset value per share of our common stock or issue securities to subscribe to, convert to or purchase shares of our common stock" for a discussion of a proposal approved by our stockholders that permits us to issue shares of our common stock below net asset value.

Delays in investing the net proceeds raised in an offering or from exiting an investment or other capital may cause our performance to be worse than that of other fully invested BDCs or other lenders or investors pursuing comparable investment strategies. We cannot assure you that we will be able to identify any investments that meet our investment objective or that any investment that we make will produce a positive return. We may be unable to invest the net proceeds of any offering or from exiting an investment or other capital on acceptable terms within the time period that we anticipate or at all, which could harm our financial condition and operating results.

We anticipate that, depending on market conditions and the amount of the capital, it may take us a substantial period of time to invest substantially all the capital in securities meeting our investment objective. During this period, we will invest the capital primarily in marketable securities and idle funds investments, which may produce returns that are significantly lower than the returns which we expect to achieve when our portfolio is fully invested in securities meeting our investment objective. As a result, any distributions that we pay during such period may be substantially lower than the distributions that we may be able to pay when our portfolio is fully invested in securities meeting our investment objective. In addition, until such time as the net proceeds of any offering or from exiting an investment or other capital are invested in securities meeting our investment objective, the market price for our common stock may decline. Thus, the initial return on your investment may be lower than when, if ever, our portfolio is fully invested in securities meeting our investment objective.

The investments we make in accordance with our investment objective may result in a higher amount of risk than alternative investment options and a higher risk of volatility or loss of principal. Our investments in portfolio companies involve higher levels of risk, and therefore, an investment in our shares may not be suitable for someone with lower risk tolerance.

Fluctuations in the trading prices of our shares may adversely affect the liquidity of the trading market for our shares and, if we seek to raise capital through future equity financings, our ability to raise such equity capital. The market price and liquidity of the market for our common stock may be significantly affected by numerous factors, some of which are beyond our control and may not be directly related to our operating performance. These factors include:

The Maryland General Corporation Law and our articles of incorporation and bylaws contain provisions that may have the effect of discouraging, delaying or making difficult a change in control of our company or the removal of our incumbent directors. The existence of these provisions, among others, may have a negative impact on the price of our common stock and may discourage third-party bids for ownership of our company. These provisions may prevent any premiums being offered to you for our common stock.

We do not own any real estate or other physical properties materially important to our operations. Currently, we lease office space in Houston, Texas for our corporate headquarters.

We may, from time to time, be involved in litigation arising out of our operations in the normal course of business or otherwise. Furthermore, third parties may try to seek to impose liability on us in connection with the activities of our portfolio companies. While the outcome of any current legal proceedings cannot at this time be predicted with certainty, we do not expect any current matters will materially affect our financial condition or results of operations; however, there can be no assurance whether any pending legal proceedings will have a material adverse effect on our financial condition or results of operations in any future reporting period.

Item 5. Market for Registrant's Common Equity, Related Stockholder Matters and Issuer Purchases of Equity Securities

Our common stock is traded on the New York Stock Exchange ("NYSE") under the symbol "MAIN." Prior to October 14, 2010, our common stock was traded on the NASDAQ Global Select Market under the same symbol "MAIN." Our common stock began trading on the NASDAQ Global Select Market on October 5, 2007. Prior to that date, there was no established public trading market for our common stock.

The following table sets forth, for each fiscal quarter since our common stock began trading, the range of high and low closing prices of our common stock as reported on the NYSE and on the NASDAQ Global Select Market.

On March 9, 2011, the last sale price of our common stock on the NYSE was $19.23 per share, and there were approximately 218 holders of record of the common stock which did not include shareholders for whom shares are held in "nominee" or "street name."

From our IPO through the third quarter of 2008, we paid quarterly dividends, but in the fourth quarter of 2008 we began paying, and we intend to continue paying, monthly dividends to our stockholders. Our monthly dividends, if any, will be determined by our Board of Directors on a quarterly basis.

Date Declared			Record Date	Payment Date	Amount(1)

Fiscal year 2010
	September 8, 2010		November 19, 2010	December 15, 2010	$	0.125	(2)
	September 8, 2010		October 21, 2010	November 15, 2010	$	0.125	(2)
	September 8, 2010		September 23, 2010	October 15, 2010	$	0.125	(2)
	June 3, 2010		August 20, 2010	September 15, 2010	$	0.125	(2)
	June 3, 2010		July 21, 2010	August 16, 2010	$	0.125	(2)
	June 3, 2010		June 21, 2010	July 15, 2010	$	0.125	(2)
	March 9, 2010		May 20, 2010	June 15, 2010	$	0.125	(2)
	March 9, 2010		April 21, 2010	May 14, 2010	$	0.125	(2)
	March 9, 2010		March 25, 2010	April 15, 2010	$	0.125	(2)
	December 8, 2009		February 22, 2010	March 15, 2010	$	0.125	(2)
	December 8, 2009		January 21, 2010	February 16, 2010	$	0.125	(2)
	December 8, 2009		January 6, 2010	January 15, 2010	$	0.125	(2)

		Total			$	1.500

Fiscal year 2009
	September 3, 2009		November 20, 2009	December 15, 2009	$	0.125	(3)
	September 3, 2009		October 21, 2009	November 16, 2009	$	0.125	(3)
	September 3, 2009		September 21, 2009	October 15, 2009	$	0.125	(3)
	June 3, 2009		August 20, 2009	September 15, 2009	$	0.125	(3)
	June 3, 2009		July 21, 2009	August 14, 2009	$	0.125	(3)
	June 3, 2009		June 19, 2009	July 15, 2009	$	0.125	(3)
	March 4, 2009		May 21, 2009	June 15, 2009	$	0.125	(3)
	March 4, 2009		April 21, 2009	May 15, 2009	$	0.125	(3)
	March 4, 2009		March 20, 2009	April 15, 2009	$	0.125	(3)
	December 3, 2008		February 20, 2009	March 16, 2009	$	0.125	(3)
	December 3, 2008		January 22, 2009	February 16, 2009	$	0.125	(3)
	December 3, 2008		December 19, 2008	January 15, 2009	$	0.125	(4)

		Total			$	1.500

Fiscal year 2008
		Total			$	1.425	(4)

Fiscal year 2007
		Total			$	0.330	(5)

Cumulative dividends declared or paid					$	5.520

To obtain and maintain RIC tax treatment, we must, among other things, distribute at least 90% of our net ordinary income and realized net short-term capital gains in excess of realized net long-term capital losses, if any. We will be subject to a 4% nondeductible federal excise tax on certain undistributed taxable income unless we distribute in a timely manner an amount at least equal to the sum of (1) 98% of our net ordinary income for each calendar year, (2) 98% of our capital gain net income for the one-year period ending October 31 in that calendar year and (3) any income recognized, but not distributed, in preceding years (the "Excise Tax Avoidance Requirement"). Dividends declared and paid by us in a year will generally differ from taxable income for that year, as such dividends may include the distribution of current year taxable income, less amounts carried over into the following year, and the distribution of prior year taxable income carried over into and distributed in the current year. For amounts we carry over into the following year, we will be required to pay a 4% excise tax for the excess over 98% of our annual taxable income in excess of distributions for the year. We may retain for investment some or all of our net capital gains (i.e., realized net long-term capital gains in excess of realized net short-term capital losses) and treat such amounts as deemed distributions to our stockholders. If we do this, our stockholders will be treated as if they had received actual distributions of the capital gains we retained and then reinvested the net after-tax proceeds in our common stock. In general, our stockholders also would be eligible to claim a tax credit (or, in certain circumstances, a tax refund) equal to their allocable shares of the tax we paid on the capital gains deemed distributed to them. We can offer no assurance that we will achieve results that will permit the payment of any cash distributions and, if we issue senior securities, we may be prohibited from making distributions if doing so causes us to fail to maintain the asset coverage ratios stipulated by the 1940 Act or if distributions are limited by the terms of any of our borrowings.

Where the IRS revenue procedure is not currently applicable, the IRS has also issued private letter rulings on cash and stock dividends paid by RICs and real estate investment trusts using a 20% cash standard (and, more recently, the 10% cash standard of the above-referenced IRS revenue procedure) if certain requirements are satisfied.

We have adopted a dividend reinvestment plan ("DRIP") that provides for the reinvestment of dividends on behalf of our stockholders, unless a stockholder has elected to receive dividends in cash. As a result, if we declare a cash dividend, our stockholders who have not "opted out" of the DRIP by the dividend record date will have their cash dividend automatically reinvested into additional shares of MSCC common stock. We have the option to satisfy the share requirements of the DRIP through the issuance of new shares of common stock or through open market purchases of common stock by the DRIP plan administrator. Newly-issued shares will be valued based upon the final closing price of MSCC's common stock on a valuation date determined by our Board of Directors. Shares purchased in the open market to satisfy the DRIP requirements will be valued based upon the average price of the applicable shares purchased by the DRIP plan administrator, before any associated brokerage or other costs.

During 2010, we issued a total of 478,731 shares of our common stock under the DRIP pursuant to an exemption from the registration requirements of the Securities Act of 1933. The aggregate offering price for the shares of our common stock issued under the DRIP during 2010 was approximately $7.6 million.

The following graph compares the stockholder return on our common stock from October 5, 2007 to December 31, 2010 with the Russell 2000 Index and the Main Street Peer Group index. This comparison assumes $100.00 was invested on October 5, 2007 (the date our common stock began to trade in connection with our initial public offering) in our common stock and in the comparison groups and assumes the reinvestment of all cash dividends prior to any tax effect. The comparisons in the graph below are based on historical data and are not intended to forecast the possible future performance of our common stock.

COMPARISON OF STOCKHOLDER RETURN(1)
Among Main Street Capital Corporation, the Russell 2000 Index and Main Street Peer Group
(For the Period October 5, 2007 to December 31, 2010)

The selected financial and other data below reflects the combined operations of MSMF and MSMF GP for the years ended December 31, 2006 and the consolidated operations of Main Street and its subsidiaries for the years ended December 31, 2007, 2008, 2009, and 2010. The selected financial data at December 31, 2006, 2007, 2008, 2009, and 2010 and for the years ended December 31, 2006, 2007, 2008, 2009, and 2010, have been derived from combined/consolidated financial statements that have been audited by Grant Thornton LLP, an independent registered public accounting firm. You should read this selected financial and other data in conjunction with our "Management's Discussion and Analysis of Financial Condition and Results of Operations" and the financial statements and related notes included in this Annual Report on Form 10-K.

			Years Ended December 31,

			2006			2007			2008			2009			2010
			(dollars in thousands)
Statement of operations data:
Investment income:
	Total interest, fee and dividend income		$	9,013		$	11,312		$	16,123		$	14,283		$	33,525
	Interest from idle funds and other			749			1,163			1,172			1,719			2,983

		Total investment income		9,762			12,475			17,295			16,002			36,508

Expenses:
	Interest			(2,717	)		(3,246	)		(3,778	)		(3,791	)		(9,058	)
	General and administrative			(198	)		(512	)		(1,684	)		(1,351	)		(1,437	)
	Expenses reimbursed to Investment Manager			—			—			(1,007	)		(570	)		(5,263	)
	Share-based compensation			—			—			(511	)		(1,068	)		(1,489	)
	Management fees to affiliate			(1,942	)		(1,500	)		—			—			—
	Professional costs related to initial public offering			—			(695	)		—			—			—

		Total expenses		(4,857	)		(5,953	)		(6,980	)		(6,780	)		(17,247	)

Net investment income				4,905			6,522			10,315			9,222			19,261
		Total net realized gain (loss) from investments		2,430			4,692			1,398			(7,798	)		(2,880	)

Net realized income				7,335			11,214			11,713			1,424			16,381
		Total net change in unrealized appreciation (depreciation) from investments		8,488			(5,406	)		(3,961	)		8,242			19,639
		Income tax benefit (provision)		—			(3,263	)		3,182			2,290			(941	)
		Bargain purchase gain		—			—			—			—			4,891

Net increase (decrease) in net assets resulting from operations				15,823			2,545			10,934			11,956			39,970
		Noncontrolling interest		—			—			—			—			(1,226	)

Net increase (decrease) in net assets resulting from operations attributable to common stock			$	15,823		$	2,545		$	10,934		$	11,956		$	38,744

Net investment income per share — basic and diluted				N/A		$	0.76		$	1.13		$	0.92		$	1.16
Net realized income per share — basic and diluted				N/A		$	1.31		$	1.29		$	0.14		$	0.99
Net increase (decrease) in net assets resulting from operations attributable to common stock per share — basic and diluted				N/A		$	0.30		$	1.20		$	1.19		$	2.38
Weighted average shares outstanding — basic and diluted				N/A			8,587,701			9,095,904			10,042,639			16,292,846

			As of December 31,

			2006			2007			2008			2009			2010
			(dollars in thousands)
Balance sheet data:
Assets:
	Total portfolio investments at fair value		$	73,711		$	105,650		$	127,007		$	156,740		$	348,811
	Marketable securities and idle funds investments			—			24,063			4,390			3,253			68,753
	Cash and cash equivalents			13,769			41,889			35,375			30,620			22,334
	Deferred tax asset			—			—			1,121			2,716			1,958
	Interest receivable and other assets			630			1,576			1,101			1,510			4,524
	Deferred financing costs, net of accumulated amortization			1,333			1,670			1,635			1,611			2,544

		Total assets	$	89,443		$	174,848		$	170,629		$	196,450		$	448,924

Liabilities and net assets:
	SBIC debentures		$	45,100		$	55,000		$	55,000		$	65,000		$	155,558
	Credit facility			—			—			—			—			39,000
	Deferred tax liability			—			3,026			—			—			—
	Interest payable			855			1,063			1,108			1,069			3,195
	Dividend payable			—			—			726			—			—
	Accounts payable and other liabilities			216			610			1,439			721			1,188

		Total liabilities		46,171			59,699			58,273			66,790			198,941
Total net asset value				43,272			115,149			112,356			129,660			245,535
Noncontrolling interest				—			—			—			—			4,448

		Total liabilities and net assets	$	89,443		$	174,848		$	170,629		$	196,450		$	448,924

Other data:
	Weighted average effective yield on LMM debt investments(1)			15.0	%		14.3	%		14.0	%		14.3	%		14.5	%
	Number of LMM portfolio companies(2)			24			27			31			35			45
	Expense ratios (as percentage of average net assets):
		Operating expenses(3)		5.5	%		4.8	%		2.8	%		2.5	%		4.0	%
		Interest expense		7.0	%		5.7	%		3.3	%		3.1	%		4.3	%

Item 7. Management's Discussion and Analysis of Financial Condition and Results of Operations

The following discussion should be read in conjunction with our financial statements and the notes thereto included elsewhere in this Annual Report on Form 10-K.

Statements we make in the following discussion which express a belief, expectation or intention, as well as those that are not historical fact, are forward-looking statements that are subject to risks, uncertainties and assumptions. Our actual results, performance or achievements, or industry results, could differ materially from those we express in the following discussion as a result of a variety of factors, including the risks and uncertainties we have referred to under the headings "Cautionary Statement Concerning Forward-Looking Statements" and "Risk Factors" in Part I of this report.

On January 7, 2010, MSCC consummated transactions (the "Exchange Offer") to exchange 1,239,695 shares of its common stock for approximately 88% of the total dollar value of the limited partner interests in Main Street Capital II, LP ("MSC II" and, together with MSMF, the "Funds"). Pursuant to the terms of the Exchange Offer, 100% of the membership interests in the general partner of MSC II, Main Street Capital II GP, LLC ("MSC II GP"), were also transferred to MSCC for no consideration. MSC II commenced operations in January 2006, is an investment fund that operates as an SBIC and is also managed by the Investment Manager. The Exchange Offer and related transactions, including the transfer of the MSC II GP interests, are collectively termed the "Exchange Offer Transactions" (see Note J to the consolidated financial statements). As of December 31, 2010, an approximately 12% minority ownership in the total dollar value of the MSC II limited partnership interests remained outstanding, including approximately 5% owned by affiliates of MSCC.

Unless otherwise noted or the context otherwise indicates, the terms "we," "us," "our" and "Main Street" refer to MSCC and its subsidiaries, including MSMF, MSC II, and the Taxable Subsidiaries.

We are a principal investment firm primarily focused on providing customized debt and equity financing to lower middle market ("LMM") companies, which we generally define as companies with annual revenues between $10 million and $100 million that operate in diverse industries. We invest primarily in secured debt instruments, equity investments, warrants and other securities of LMM companies based in the United States. Our principal investment objective is to maximize our portfolio's total return by generating current income from our debt investments and capital appreciation from our equity and equity-related investments, including

warrants, convertible securities and other rights to acquire equity securities in a portfolio company. Our LMM portfolio investments generally range in size from $3 million to $20 million.

In addition to our investment strategy of investing in LMM companies, we opportunistically pursue investments in privately placed debt securities. This private placement investment portfolio primarily consists of direct or secondary private placements of interest-bearing securities in companies that are generally larger in size than the LMM companies included in our investment portfolio. As of December 31, 2010, we had privately placed portfolio investments in 16 companies collectively totaling approximately $67.1 million in fair value with a total cost basis of approximately $65.6 million. The weighted average revenues for the 16 privately placed portfolio company investments was approximately $352 million. All of our privately placed portfolio investments were in the form of debt investments and 71% of such debt investments at cost were secured by first priority liens on portfolio company assets. The weighted average effective yield on Main Street's privately placed portfolio debt investments was approximately 12.5% as of December 31, 2010.

Our portfolio investments are generally made through MSCC and the Funds. MSCC and the Funds share the same investment strategies and criteria, although they are subject to different regulatory regimes. An investor's return in MSCC will depend, in part, on the Funds' investment returns as MSMF is a wholly owned subsidiary of MSCC and MSC II is a majority owned subsidiary of MSCC.

The level of new portfolio investment activity will fluctuate from period to period based upon our view of the current economic fundamentals, our ability to identify new investment opportunities that meet our investment criteria, and our ability to consummate identified opportunities. The level of new investment activity, and associated interest and fee income, will directly impact future investment income. In addition, the level of dividends paid by portfolio companies and the portion of our portfolio debt investments on non-accrual status will directly impact future investment income. While we intend to grow our portfolio and our investment income over the long-term, our growth and our operating results may be more limited during depressed economic periods. However, we intend to appropriately manage our cost structure and liquidity position based on applicable economic conditions and our investment outlook. The level of realized gains or losses and unrealized appreciation or depreciation will also fluctuate depending upon portfolio activity and the performance of our individual portfolio companies. The changes in realized gains and losses and unrealized appreciation or depreciation could have a material impact on our operating results.

For the year ended December 31, 2010, we paid dividends on a monthly basis totaling $1.50 per share, or $23.9 million. We generated undistributed taxable income (or "spillover income") of approximately $1.6 million, or $0.09 per share, during 2010 that will be carried forward toward distributions paid in 2011. In December 2010, we declared monthly dividends for the first quarter of 2011 totaling $0.375 per share. In March 2011, we declared monthly dividends for the second quarter of 2011 totaling $0.39 per share. Including the dividends declared for the first and second quarters of 2011, we will have paid approximately $5.52 per share in cumulative dividends since our October 2007 initial public offering.

At December 31, 2010, we had $91.1 million in cash and cash equivalents, marketable securities, and idle funds investments. In August 2010, we completed a follow-on public stock offering in which we sold 3,220,000 shares of common stock, including the underwriters' exercise of the over-allotment option, at a price to the public of $15.00 per share (or approximately 123% of the then latest reported Net Asset Value

per share), resulting in total net proceeds of approximately $45.8 million, after deducting underwriters' commissions and offering costs. In January 2010, we completed a follow-on public stock offering in which we sold 2,875,000 shares of common stock, including the underwriters' exercise of the over-allotment option, at a price to the public of $14.75 per share (or approximately 123% of the then latest reported Net Asset Value per share), resulting in total net proceeds of approximately $40.1 million, after deducting underwriters' commissions and offering costs.

The American Recovery and Reinvestment Act of 2009 enacted in February 2009 (the "Stimulus Bill") contains several provisions applicable to SBIC funds, including the Funds. One of the key SBIC-related provisions included in the Stimulus Bill increased the maximum amount of combined SBIC leverage (or SBIC leverage cap) to $225 million for affiliated SBIC funds. The prior maximum amount of SBIC leverage available to affiliated SBIC funds was approximately $137 million. Since the increase in the SBIC leverage cap applies to affiliated SBIC funds, Main Street is required to allocate such increased borrowing capacity between the Funds. Main Street has access to an incremental $45 million in SBIC leverage capacity, subject to the required capitalization of each of the Funds, in addition to the $180 million of existing SBIC leverage at the Funds.

A proposed bill, the Small Business Financing and Investment Act of 2009, or HR 3854, would increase the total SBIC leverage capacity for affiliated SBIC funds from $225 million to $350 million. If enacted, this bill would increase Main Street's SBIC leverage capacity through the Funds by an additional $125 million. While Main Street is positioned to benefit from the full congressional passage of HR 3854, the ultimate form and likely outcome of such legislation or any similar legislation cannot be predicted.

In our view, the SBIC leverage, including the increased capacity, remains a strategic advantage due to its long-term, flexible structure and its low fixed cost. The SBIC leverage also provides proper matching of duration and cost compared with our LMM portfolio investments. As of December 31, 2010, the weighted average duration of our LMM portfolio debt investments was approximately 3.1 years compared to a weighted average duration of 7.1 years for our SBIC leverage. As of December 31, 2010, approximately 90% of LMM portfolio debt investments bear interest at fixed rates which is also appropriately matched by the long-term, low cost fixed rates available through our SBIC leverage.

Our financial statements are prepared in accordance with U.S. generally accepted accounting principles ("U.S. GAAP"). For the year ended December 31, 2010, our consolidated financial statements include the accounts of MSCC and its consolidated subsidiaries, including MSMF and MSC II. For the year ended 2009, our consolidated financial statements include the accounts of MSCC and its consolidated subsidiaries, including MSMF. Portfolio investments, as used herein, refers to all of our portfolio investments in LMM companies, private placement portfolio investments, and the Investment Manager and excludes all "Marketable securities and idle funds investments." Private placement portfolio investments include investments made through direct or secondary purchases of interest-bearing securities in companies that are generally larger in size than the LMM companies included as part of our portfolio investments. "Marketable securities and idle funds investments" are classified as financial instruments and are reported separately on our Consolidated Balance Sheets and Consolidated Schedule of Investments due to the nature of such investments. Our results of operations and cash flows for the years ended December 31, 2010, 2009, and 2008, and financial position as of December 31, 2010 and 2009, are presented on a consolidated basis. The effects of all intercompany transactions between Main Street and its consolidated subsidiaries have been eliminated in consolidation. Certain reclassifications have been made to prior period balances to conform with the current financial statement presentation, including the reclassification of private placement portfolio investments which were formerly classified as "Marketable securities and idle funds investments" and are now classified as portfolio investments in the "Non-Control/Non-Affiliate investments" category due to our current intent to hold such investments until their maturity and the fact that their terms adhere more to our portfolio investment strategy.

Under the investment company rules and regulations pursuant to Article 6 of Regulation S-X and the Audit and Accounting Guide for Investment Companies issued by the American Institute of Certified Public Accountants (the "AICPA Guide"), we are precluded from consolidating portfolio company investments, including those in which we have a controlling interest, unless the portfolio company is another investment company. An exception to this general principle in the AICPA Guide occurs if we own a controlled operating company that provides all or substantially all of its services directly to us, or to an investment company of ours. None of the investments made by us qualify for this exception. Therefore, our portfolio investments are carried on the balance sheet at fair value, as discussed further in Note B to our consolidated financial statements, with any adjustments to fair value recognized as "Net Change in Unrealized Appreciation (Depreciation)" on our Statement of Operations until the investment is exited, resulting in any gain or loss on exit being recognized as a "Net Realized Gain (Loss) from Investments."

The most significant estimate inherent in the preparation of our consolidated financial statements is the valuation of our portfolio investments and the related amounts of unrealized appreciation and depreciation. As of December 31, 2010 and 2009, approximately 78% and 80%, respectively, of our total assets represented investments in portfolio companies valued at fair value (including the investment in the Investment Manager). We are required to report our investments at fair value. We adopted the provisions of the Accounting Standards Codification ("Codification" or "ASC") 820, Fair Value Measurements and Disclosures in the first quarter of 2008. ASC 820 defines fair value, establishes a framework for measuring fair value, establishes a fair value hierarchy based on the quality of inputs used to measure fair value, and enhances disclosure requirements for fair value measurements.

Our portfolio strategy calls for us to invest primarily in illiquid securities issued by private, LMM companies. These LMM portfolio investments may be subject to restrictions on resale and will generally have no established trading market. We determine in good faith the fair value of our LMM portfolio investments pursuant to a valuation policy in accordance with ASC 820 and a valuation process approved by our Board of Directors and in accordance with the 1940 Act. We review external events, including private mergers, sales and acquisitions involving comparable companies, and include these events in the valuation process. Our valuation policy and process are intended to provide a consistent basis for determining the fair value of the portfolio.

For valuation purposes, control investments are composed of equity and debt securities for which we have a controlling interest in the portfolio company or have the ability to nominate a majority of the portfolio company's board of directors. Market quotations are generally not readily available for our control investments. As a result, we determine the fair value of control investments using a combination of market and income approaches. Under the market approach, we will typically use the enterprise value methodology to determine the fair value of these investments. The enterprise value is the fair value at which an enterprise could be sold in a transaction between two willing parties, other than through a forced or liquidation sale. Typically, private companies are bought and sold based on multiples of earnings before interest, taxes, depreciation and amortization, or EBITDA, cash flows, net income, revenues, or in limited cases, book value. There is no single methodology for estimating enterprise value. For any one portfolio company, enterprise value is generally described as a range of values from which a single estimate of enterprise value is derived. In estimating the enterprise value of a portfolio company, we analyze various factors, including the portfolio company's historical and projected financial results. We allocate the enterprise value to investments in order of the legal priority of the investments. We will also use the income approach to determine the fair value of these securities, based on projections of the discounted future free cash flows that the portfolio company or the debt security will likely generate. The valuation approaches for our control investments estimate the value of the investment if we were to sell, or exit, the investment, assuming the highest and best use of the investment by market participants. In addition, these valuation approaches consider the value associated with our ability to control the capital structure of the portfolio company, as well as the timing of a potential exit.

For valuation purposes, non-control LMM portfolio investments are composed of debt and equity securities for which we do not have a controlling interest in the portfolio company, or the ability to nominate

a majority of the portfolio company's board of directors. Market quotations for non-control LMM investments are generally not readily available. For our non-control LMM portfolio investments, we use a combination of the market and income approaches to value our equity investments and the income approach to value our debt instruments. For non-control LMM debt investments, we determine the fair value primarily using a yield approach that analyzes the discounted cash flows of interest and principal for the debt security, as set forth in the associated loan agreements, as well as the financial position and credit risk of each of these portfolio investments. Our estimate of the expected repayment date of a LMM debt security is generally the legal maturity date of the instrument, as we generally intend to hold our loans to maturity. The yield analysis considers changes in leverage levels, credit quality, portfolio company performance and other factors. We will use the value determined by the yield analysis as the fair value for that security; however, because of our general intent to hold our loans to maturity, the fair value will not exceed the face amount of the LMM debt security. A change in the assumptions that we use to estimate the fair value of our LMM debt securities using the yield analysis could have a material impact on the determination of fair value. If there is deterioration in credit quality or a debt security is in workout status, we may consider other factors in determining the fair value of a LMM debt security, including the value attributable to the debt security from the enterprise value of the portfolio company or the proceeds that would be received in a liquidation analysis.

Our private placement portfolio investments primarily consist of direct or secondary purchases of interest-bearing securities in companies that are generally larger in size than the LMM companies included in our investment portfolio. For valuation purposes, all of our private placement portfolio investments are non-control investments and are composed of debt securities for which we do not have a controlling interest in the portfolio company, or the ability to nominate a majority of the portfolio company's board of directors. We primarily use observable inputs to determine the fair value of these investments through obtaining third party quotes or independent pricing.

Due to the inherent uncertainty in the valuation process, our estimate of fair value may differ materially from the values that would have been used had a ready market for the securities existed. In addition, changes in the market environment, portfolio company performance and other events that may occur over the lives of the investments may cause the gains or losses ultimately realized on these investments to be materially different than the valuations currently assigned. We estimate the fair value of each individual investment and record changes in fair value as unrealized appreciation or depreciation.

We record interest and dividend income on the accrual basis to the extent amounts are expected to be collected. Dividend income is recorded as dividends are declared or at the point an obligation exists for the portfolio company to make a distribution. In accordance with our valuation policy, we evaluate accrued interest and dividend income periodically for collectability. When a loan or debt security becomes 90 days or more past due, and if we otherwise do not expect the debtor to be able to service all of its debt or other obligations, we will generally place the loan or debt security on non-accrual status and cease recognizing interest income on that loan or debt security until the borrower has demonstrated the ability and intent to pay contractual amounts due. If a loan or debt security's status significantly improves regarding ability to service the debt or other obligations, or if a loan or debt security is fully impaired, sold or written off, we will remove it from non-accrual status.

We may periodically provide services, including structuring and advisory services, to our portfolio companies. For services that are separately identifiable and evidence exists to substantiate fair value, income is recognized as earned, which is generally when the investment or other applicable transaction closes. Fees received in connection with debt financing transactions for services that do not meet these criteria are treated as debt origination fees and are accreted into interest income over the life of the financing.

While not significant to the total portfolio, we hold debt and preferred equity instruments in our investment portfolio that contain payment-in-kind ("PIK") interest and cumulative dividend provisions. The PIK interest, computed at the contractual rate specified in each debt agreement, is added to the principal balance of the debt and is recorded as interest income. Thus, the actual collection of this interest may be deferred until the time of debt principal repayment. Cumulative dividends are recorded as dividend income, and any dividends in arrears are added to the balance of the preferred equity investment. The actual collection of dividends in arrears may be deferred until such time as the preferred equity is redeemed. To maintain regulated investment company ("RIC") tax treatment (as discussed below), these non-cash sources of income will need to be paid out to stockholders in the form of distributions, even though we may not have collected the PIK interest and cumulative dividends in cash. We will stop accruing PIK interest and cumulative dividends and will write off any accrued and uncollected interest and dividends in arrears when it is determined that such PIK interest and dividends in arrears are no longer collectible.

We account for our share-based compensation plans using the fair value method, as prescribed by ASC 718, Compensation — Stock Compensation. Accordingly, for restricted stock awards, we measured the grant date fair value based upon the market price of our common stock on the date of the grant and will amortize this fair value to share-based compensation expense over the requisite service period or vesting term.

MSCC has elected and intends to continue to qualify for the tax treatment applicable to a RIC under Subchapter M of the Internal Revenue Code of 1986, as amended (the "Code"), and, among other things, intends to make the required distributions to its stockholders as specified therein. In order to qualify as a RIC, MSCC is required to timely distribute to its stockholders at least 90% of investment company taxable income, as defined by the Code, each year. Depending on the level of taxable income earned in a tax year, MSCC may choose to carry forward taxable income in excess of current year distributions into the next tax year and pay a 4% excise tax on such income. Any such carryover taxable income must be distributed through a dividend declared prior to filing the final tax return related to the year which generated such taxable income.

The Taxable Subsidiaries hold certain portfolio investments of Main Street. The Taxable Subsidiaries are consolidated for U.S. GAAP reporting purposes, and the portfolio investments held by them are included in Main Street's consolidated financial statements. The Taxable Subsidiaries permit Main Street to hold equity investments in portfolio companies which are "pass through" entities for tax purposes in order to comply with the "source income" requirements contained in the RIC tax provisions. The Taxable Subsidiaries are not consolidated with Main Street for income tax purposes and may generate income tax expense, or benefit, as a result of their ownership of certain portfolio investments. This income tax expense, or benefit, is reflected in Main Street's Consolidated Statement of Operations.

The Taxable Subsidiaries use the liability method in accounting for income taxes. Deferred tax assets and liabilities are recorded for temporary differences between the tax basis of assets and liabilities and their reported amounts in the financial statements, using statutory tax rates in effect for the year in which the temporary differences are expected to reverse. A valuation allowance is provided against deferred tax assets when it is more likely than not that some portion or all of the deferred tax asset will not be realized.

Taxable income generally differs from net income for financial reporting purposes due to temporary and permanent differences in the recognition of income and expenses. Taxable income generally excludes net unrealized appreciation or depreciation, as investment gains or losses are not included in taxable income until they are realized.

LMM portfolio investments principally consist of secured debt, equity warrants and direct equity investments in privately held, LMM companies. The LMM debt investments are secured by either a first or second lien on the assets of the portfolio company, generally bear interest at fixed rates, and generally mature between five and seven years from the original investment. In most LMM portfolio companies, we also receive nominally priced equity warrants and/or make direct equity investments, usually in connection with a debt investment.

Summaries of the composition of our LMM investment portfolio at cost and fair value as a percentage of total LMM portfolio investments are shown in the following table:

The following table shows the LMM portfolio composition by geographic region of the United States at cost and fair value as a percentage of total LMM portfolio investments. The geographic composition is determined by the location of the corporate headquarters of the portfolio company:

Main Street's LMM portfolio investments are generally in companies conducting business in a variety of industries. Set forth below are tables showing the composition of Main Street's LMM portfolio investments by industry at cost and fair value as of December 31, 2010 and 2009:

Cost:

Professional services	15.4	%	12.7	%
Equipment rental	8.4	%	3.6	%
Information services	7.8	%	5.1	%
Retail	7.4	%	7.5	%
Industrial equipment	7.2	%	6.4	%
Industrial services	7.2	%	5.0	%
Media/Marketing	6.6	%	0.0	%
Metal fabrication	6.3	%	2.5	%
Electronics manufacturing	5.2	%	7.1	%
Health care services	5.0	%	4.7	%
Precast concrete manufacturing	4.4	%	9.7	%
Restaurant	3.3	%	5.6	%
Custom wood products	3.0	%	6.7	%
Agricultural services	2.8	%	6.6	%
Consumer Products	2.6	%	0.0	%
Manufacturing	2.4	%	4.1	%
Governmental services	1.8	%	2.0	%
Transportation/Logistics	1.3	%	6.1	%
Health care products	1.2	%	3.0	%
Infrastructure products	0.7	%	1.6	%

	100.0	%	100.0	%

Fair Value:

Professional services	14.3	%	12.2	%
Information services	8.5	%	4.4	%
Industrial services	7.8	%	7.0	%
Equipment rental	7.3	%	2.3	%
Health care services	7.1	%	9.1	%
Retail	6.6	%	6.6	%
Metal fabrication	6.5	%	4.5	%
Industrial equipment	6.3	%	5.2	%
Media/Marketing	5.9	%	0.0	%
Electronics manufacturing	5.0	%	6.2	%
Precast concrete manufacturing	4.9	%	11.5	%
Restaurant	3.7	%	6.2	%
Agricultural services	3.3	%	7.9	%
Custom wood products	3.0	%	1.6	%
Manufacturing	2.7	%	3.9	%
Consumer Products	2.3	%	0.0	%
Transportation/Logistics	1.8	%	6.3	%
Governmental services	1.8	%	2.1	%
Health care products	1.1	%	2.9	%
Infrastructure products	0.1	%	0.1	%

	100.0	%	100.0	%

Our LMM portfolio investments carry a number of risks including, but not limited to: (1) investing in LMM companies which may have a limited operating history and financial resources; (2) holding investments that are not publicly traded and which may be subject to legal and other restrictions on resale; and (3) other risks common to investing in below investment grade debt and equity investments in private, LMM companies.

We utilize an internally developed investment rating system to rate the performance of each portfolio company. Investment Rating 1 represents a portfolio company that is performing in a manner which significantly exceeds expectations and projections. Investment Rating 2 represents a portfolio company that, in general, is performing above expectations. Investment Rating 3 represents a portfolio company that is generally performing in accordance with expectations. Investment Rating 4 represents a portfolio company that is underperforming expectations. Investments with such a rating require increased monitoring and scrutiny by us. Investment Rating 5 represents a portfolio company that is significantly underperforming. Investments with such a rating require heightened levels of monitoring and scrutiny by us and involve the recognition of significant unrealized depreciation on such investment. All new portfolio investments receive an initial 3 rating.

The following table shows the distribution of our LMM and privately placed portfolio investments (excluding the investment in our affiliated Investment Manager) on the 1 to 5 investment rating scale at fair value as of December 31, 2010 and 2009:

The broader fundamentals of the United States economy remain mixed, and unemployment remains elevated. In the event that the United States economy contracts, it is likely that the financial results of small- to mid-sized companies, like those in which we invest, could experience deterioration or limited growth from current levels, which could ultimately lead to difficulty in meeting their debt service requirements and an increase in defaults. In addition, the end markets for certain of our portfolio companies' products and services have experienced negative economic trends over the last few years. Consequently, we can provide no assurance that the performance of certain portfolio companies will not be negatively impacted by these economic or other conditions, which could also have a negative impact on our future results.

	Years Ended December 31,						Net Change

	2010			2009			Amount			%
	(dollars in millions)
Total investment income	$	36.5		$	16.0		$	20.5			128	%
Total expenses		(17.2	)		(6.8	)		(10.4	)		154	%

Net investment income		19.3			9.2			10.1			109	%
Total net realized loss from investments		(2.9	)		(7.8	)		4.9			NM

Net realized income		16.4			1.4			15.0			1050	%
Net change in unrealized appreciation		19.6			8.2			11.4			138	%
Income tax benefit (provision)		(1.0	)		2.3			(3.3	)		-141	%
Bargain purchase gain		4.9			—			4.9			NM
Noncontrolling interest		(1.2	)		—			(1.2	)		NM

Net increase in net assets resulting from operations attributable to common stock	$	38.7		$	11.9		$	26.8			224	%

For the year ended December 31, 2010, total investment income was $36.5 million, a $20.5 million, or 128%, increase over the $16.0 million of total investment income for the year ended December 31, 2009. This comparable period increase was principally attributable to (i) $13.1 million of total investment income from portfolio investments held by MSC II, the fund acquired as part of the Exchange Offer, (ii) a $6.7 million increase in interest income from higher average levels of both portfolio debt investments and interest-bearing marketable securities or idle funds investments, (iii) a $0.5 million increase in non-recurring interest income in the fourth quarter of 2010 due to higher levels of prepayment activity from our portfolio debt investments, and (iv) a $0.3 million increase in fee income due to higher levels of transaction activity, partially offset by a $0.1 million decrease in dividend income principally due to a $0.9 million special dividend from a portfolio company investment that was received in the third quarter of 2009.

For the year ended December 31, 2010, total expenses increased by approximately $10.4 million, or 154%, to $17.2 million from $6.8 million for the year ended December 31, 2009. This comparable period increase in expenses was principally attributable to (i) $7.8 million in interest expense and other operating expenses related to MSC II subsequent to the Exchange Offer, (ii) higher share-based compensation expense of $0.3 million related to non-cash amortization for restricted share grants, (iii) higher interest expense of $0.7 million as a result of an additional $20.0 million in SBIC Debentures issued through MSMF during 2010 and borrowings under our credit facility during the fourth quarter of 2010, and (iv) higher personnel costs and other operating expenses.

Distributable net investment income for the year ended December 31, 2010 was $20.7 million, or a 102% increase, compared to distributable net investment income of $10.3 million during the year ended December 31, 2009. The increase in distributable net investment income was primarily due to higher levels of total investment income partially offset by higher interest and other operating expenses, due to the changes discussed above. Distributable net investment income on a per share basis for 2010 reflects a greater number of average shares outstanding compared to 2009 due to the January and August 2010 follow-on stock offerings, as well as the shares issued to consummate the Exchange Offer.

Net investment income for the year ended December 31, 2010 was $19.3 million, or a 109% increase, compared to net investment income of $9.2 million during the year ended December 31, 2009. The increase in net investment income was principally attributable to the increase in total investment income, partially offset by higher interest and other operating expenses as discussed above.

For the year ended December 31, 2010, the net realized loss from investments of $2.9 million was primarily attributable to (i) $4.0 million of realized loss on our debt and equity investment in Quest Design and Production, LLC in the first quarter of 2010 and (ii) $1.9 million of realized loss on our debt and equity investment in Advantage Millwork Company, Inc. in the third quarter of 2010, partially offset by (i) $2.3 million of realized gain during the second quarter of 2010 on the partial exits of equity investments in Laurus Healthcare, LP and Gulf Manufacturing, LLC and on the full exit of our equity investment in Pulse Systems, LLC and (ii) $0.7 million of net realized gain related to private placement, marketable securities, and idle funds investments. The net realized loss of $7.8 million during the 2009 year related to realized losses recognized on the exit of our investments in two portfolio companies, partially offset by net realized gain on the partial exit of our equity investments in one portfolio company and net realized gain attributable to marketable securities investments.

Distributable net realized income increased $15.3 million to $17.8 million, or $1.08 per share, for 2010 compared with distributable net realized income of $2.5 million, or $0.25 per share, in 2009 due to the higher levels of distributable net investment income as well as the change in total net realized loss from investments.

The higher levels of net investment income for the year ended December 31, 2010, partially offset by the change in total net realized loss during that period, resulted in a $15.0 million increase in net realized income compared with 2009.

For the year ended December 31, 2010, the $19.6 million net change in unrealized appreciation was principally attributable to (i) $2.8 million in accounting reversals of net unrealized depreciation attributable to the net realized loss recognized during 2010 as discussed above, (ii) unrealized appreciation on 29 portfolio investments totaling $18.3 million, offset by unrealized depreciation on 18 portfolio investments totaling $8.8 million, (iii) $6.9 million in unrealized appreciation attributable to our SBIC debentures, (iv) $0.6 million in unrealized appreciation attributable to investments in marketable securities, and (v) $0.3 million in unrealized depreciation attributable to our investment in the affiliated Investment Manager. The noncontrolling interest of $1.2 million recognized during 2010 reflected the pro rata portion of MSC II net earnings attributable to the equity interests in MSC II not owned by Main Street. During the first quarter of 2010, we also recognized a $4.9 million bargain purchase gain related to the consummation of the Exchange Offer. The bargain purchase gain recognized during the first quarter of 2010 is a non-recurring gain which was solely generated by the acquisition accounting related to the Exchange Offer. For the year ended December 31, 2010, we also recognized a net income tax provision of $1.0 million principally related to deferred taxes on unrealized appreciation of equity investments held in our Taxable Subsidiaries.

As a result of these events, our net increase in net assets resulting from operations attributable to common stock during 2010 was $38.7 million, or $2.38 per share, compared with a net increase in net assets resulting from operations attributable to common stock of $11.9 million, or $1.19 per share, in 2009.

For the year ended December 31, 2009, total investment income was $16.0 million, a $1.3 million, or 7%, decrease over the $17.3 million of total investment income for the year ended December 31, 2008. This comparable period decrease was principally attributable to (i) lower dividend income of $1.4 million due to certain portfolio companies retaining their excess cash flow as additional cushion given reduced economic visibility and lower near-term earnings expectations and (ii) reduced levels of fee income of $1.3 million due to lower new investment originations; partially offset by higher interest income of $1.4 million from LMM and privately placed portfolio debt investments and from marketable securities and idle funds investments on higher average levels of such investments.

For the year ended December 31, 2009, total expenses decreased by approximately $0.2 million, or 3%, to $6.8 million from $7.0 million for the year ended December 31, 2008. The decrease in total expenses was primarily attributable to a $0.8 million reduction in general, administrative and other overhead expenses. The reduction in general, administrative and overhead costs primarily related to (i) lower accrued compensation expense given lower investment income levels, (ii) consulting fees received by the affiliated Investment Manager during 2009 and (iii) reduced costs for certain legal and administrative activities based upon developing internal resources to perform such activities. The decrease in general, administrative and other overhead expenses was partially offset by a $0.6 million increase in share-based compensation expense related to non-cash amortization for restricted share grants.

Distributable net investment income for the year ended December 31, 2009 was $10.3 million, or a 5% decrease, compared to distributable net investment income of $10.8 million during the year ended December 31, 2008. The decrease in distributable net investment income was primarily attributable to reduced levels of total investment income, partially offset by lower general, administrative and overhead expenses as discussed above.

Net investment income for the year ended December 31, 2009 was $9.2 million, or an 11% decrease, compared to net investment income of $10.3 million during the year ended December 31, 2008. The decrease in net investment income was principally attributable to the decrease in total investment income, partially offset by lower general, administrative and overhead expenses as discussed above.

For the year ended December 31, 2009, distributable net realized income was $2.5 million, or a $9.7 million decrease compared to distributable net realized income of $12.2 million for the year ended December 31, 2008. The decrease in distributable net realized income was primarily attributable to the level of net realized loss during 2009 and the decrease in distributable net investment income. The net realized loss of $7.8 million during 2009 principally related to realized losses recognized on the exit of our investments in two portfolio companies, partially offset by realized gains related to the partial exit of our equity investments in one portfolio company and realized gains related to marketable securities investments. The net realized gain of $1.4 million during 2008 principally related to realized gains recognized on equity investments in four portfolio companies, offset by realized losses on debt and equity investments in two portfolio companies.

The lower net investment income for the year ended December 31, 2009 coupled with the higher level of net realized loss during that period resulted in a $10.3 million decrease in the net realized income for the year ended December 31, 2009 compared with 2008.

For the year ended December 31, 2009, we recorded a net change in unrealized appreciation in the amount of $8.2 million, or a $12.2 million increase, compared to the $4.0 million net change in unrealized depreciation for the year ended December 31, 2008. The $8.2 million net change in unrealized appreciation for the 2009 year was principally attributable to (i) $8.3 million in accounting reversals of net unrealized depreciation attributable to the total net realized loss on the exit of the portfolio investments and marketable securities investments discussed above, (ii) unrealized appreciation on fourteen investments in portfolio companies totaling $11.6 million, partially offset by unrealized depreciation on fifteen investments in portfolio companies totaling $11.7 million, (iii) $0.6 million in unrealized appreciation related to marketable securities investments and (iv) $0.6 million in unrealized depreciation attributable to our investment in the affiliated Investment Manager. For the 2009 year, we also recognized a net income tax benefit of $2.3 million principally related to deferred taxes on unrealized depreciation for certain portfolio investments held in our taxable subsidiary.

As a result of these events, our net increase in net assets resulting from operations during the year ended December 31, 2009 was $11.9 million compared to a net increase in net assets resulting from operations of $10.9 million for the year ended December 31, 2008.

For the year ended December 31, 2010, we experienced a net decrease in cash and cash equivalents in the amount of $8.3 million. During that period, we generated $16.6 million of cash from our operating activities, primarily from distributable net investment income partially offset by (i) the semi-annual interest payments made on our SBIC debentures, (ii) increases in interest receivable, (iii) accretion of unearned income, and (iv) non-cash interest and dividends. We used $176.0 million in net cash from investing activities, principally including the funding of $157.7 million for new portfolio company investments and the funding of $100.6 million for marketable securities and idle funds investments, partially offset by (i) $36.8 million of cash proceeds from the sale of marketable securities and idle funds investments, (ii) $43.0 million in cash proceeds from the repayment of portfolio debt investments and from the exit of portfolio equity investments, and (iii) $2.5 million in cash acquired as part of the Exchange Offer. During 2010, $151.1 million in cash was provided by financing activities, which principally consisted of (i) $85.9 million in net cash proceeds from public stock offerings in January 2010 and August 2010, (ii) $45.0 million in cash proceeds from the issuance of SBIC debentures, and (iii) $39 million in net cash proceeds from our credit facility, partially offset by $16.3 million in cash dividends paid to stockholders and $2.1 million in loan costs associated with our SBIC debentures and credit facility.

For the year ended December 31, 2009, we experienced a net decrease in cash and cash equivalents in the amount of $4.8 million. During that period, we generated $8.0 million of cash from our operating activities, primarily from distributable net investment income partially offset by (i) the semi-annual interest payments on our SBIC debentures, (ii) decreases in accounts payable, and (iii) non-cash interest and dividends. We used $26.0 million in net cash from investing activities, principally including the funding of $85.9 million for marketable securities and idle funds investments and the funding of $24.7 million for new portfolio company investments, partially offset by $73.5 million of cash proceeds from the sale of marketable securities and idle funds investments and $11.1 million in cash proceeds from the repayment of portfolio debt investments. During 2009, $13.2 million in cash was provided by financing activities, which principally consisted of $16.2 million in net cash proceeds from a June 2009 public stock offering and $9.6 million in net proceeds from the issuance of SBIC debentures, partially offset by $11.2 million in cash dividends and $1.6 million in purchases of shares of our common stock as part of our share repurchase program.

For the year ended December 31, 2008, we experienced a net decrease in cash and cash equivalents of $6.5 million. During that period, we generated $10.9 million of cash from our operating activities, primarily from distributable net investment income partially offset by the semi-annual interest payments on our SBIC debentures. We used $3.5 million in net cash for investing activities, principally due to the funding of new investments and several smaller follow-on investments for a total of $47.7 million. We also made a $4.2 million investment in idle funds investments, and received proceeds from the maturity of a $24.1 million investment in idle funds investments. We received $16.3 million in cash proceeds from repayment of debt investments and $8.0 million of cash proceeds from the redemption and sale of equity investments. For the year ended December 31, 2008, we used $13.9 million in cash for financing activities, which principally consisted of $13.2 million in cash dividends to stockholders, $0.4 million in deferred loan origination costs and $0.3 million used in the purchase of share of our common stock pursuant to our share repurchase program, which has since been terminated.

As of December 31, 2010, we had $91.1 million in cash and cash equivalents, marketable securities, and idle funds investments, and our net asset value totaled $245.5 million, or $13.06 per share. In September 2010, we entered into an $85 million, three-year credit facility (the "Credit Facility") with a group of bank lenders, and in January 2011, we expanded the Credit Facility from $85 million to $100 million. The purpose of the Credit Facility is to provide additional liquidity in support of future investment and operational activities. The revisions to the Credit Facility provide several benefits to Main Street, including (i) an expansion of the total

committed facility size to $100 million compared with Main Street's prior $30 million credit facility, (ii) increased advance rates applicable to Main Street's eligible investments, (iii) the addition of new lenders which further diversifies the Main Street lending group to a total of six participants, and (iv) an extension of the maturity date to September 20, 2013. The accordion feature of the Credit Facility allows us to seek up to $150 million of total commitments from new or existing lenders on the same terms and conditions as the existing commitments. Borrowings under the Credit Facility bear interest, subject to Main Street's election, on a per annum basis equal to (i) the applicable LIBOR rate plus 2.50% or (ii) the applicable base rate plus 1.50%. Main Street pays unused commitment fees of 0.375% per annum on the average unused lender commitments under the Credit Facility. The Credit Facility is secured by a first lien on the assets of MSCC and its subsidiaries, excluding the assets of the Funds. The Credit Facility contains certain affirmative and negative covenants, including but not limited to: (i) maintaining an interest coverage ratio of at least 2.0 to 1.0, (ii) maintaining an asset coverage ratio of at least 2.5 to 1.0, and (iii) maintaining a minimum tangible net worth. At December 31, 2010, Main Street had $39 million in borrowings outstanding under the Credit Facility and recognized $519,439 in interest expense for the year ended December 31, 2010 related to its credit facilities. As of December 31, 2010, Main Street was in compliance with all financial covenants of the Credit Facility.

In August 2010, we completed a follow-on public stock offering in which we sold 3,220,000 shares of common stock, including the underwriters' exercise of the over-allotment option, at a price to the public of $15.00 per share (or approximately 123% of the then latest reported Net Asset Value per share), resulting in total net proceeds of approximately $45.8 million, after deducting underwriters' commissions and offering costs. In January 2010, we completed a follow-on public stock offering in which we sold 2,875,000 shares of common stock, including the underwriters' exercise of the over-allotment option, at a price to the public of $14.75 per share (or approximately 123% of the then latest reported Net Asset Value per share), resulting in total net proceeds of approximately $40.1 million, after deducting underwriters' commissions and offering costs.

Due to each of the Funds' status as a licensed SBIC, we have the ability to issue, through the Funds, debentures guaranteed by the SBA at favorable interest rates. Under the regulations applicable to SBIC funds, an SBIC can have outstanding debentures guaranteed by the SBA generally in an amount up to twice its regulatory capital, which effectively approximates the amount of its equity capital. Debentures guaranteed by the SBA have fixed interest rates that equal prevailing 10-year Treasury Note rates plus a market spread and have a maturity of ten years with interest payable semi-annually. The principal amount of the debentures is not required to be paid before maturity but may be pre-paid at any time. Debentures issued prior to September 2006 were subject to pre-payment penalties during their first five years. Those pre-payment penalties no longer apply to debentures issued after September 1, 2006. On December 31, 2010, we, through the Funds, had $180 million of outstanding indebtedness guaranteed by the SBA, which carried a weighted average fixed interest rate of approximately 5.2%. The first maturity related to the SBIC debentures does not occur until 2013, and the weighted average duration is 7.1 years as of December 31, 2010.

The Stimulus Bill contains several provisions applicable to SBIC funds, including the Funds. One of the key SBIC-related provisions included in the Stimulus Bill increased the maximum amount of combined SBIC leverage (or SBIC leverage cap) to $225 million for affiliated SBIC funds. The prior maximum amount of SBIC leverage available to affiliated SBIC funds was approximately $137 million. Since the increase in the SBIC leverage cap applies to affiliated SBIC funds, Main Street is required to allocate such increased borrowing capacity between the Funds. Subsequent to the Exchange Offer, Main Street now has access to an incremental $45 million in SBIC leverage capacity, subject to the required capitalization of each of the Funds, in addition to the $95 million of existing MSC II SBIC leverage and the $85 million of MSMF SBIC leverage.

While Main Street is positioned to benefit from the full congressional passage of HR 3854, the ultimate form and likely outcome of such legislation or any similar legislation cannot be predicted.

We anticipate that we will continue to fund our investment activities through existing cash and cash equivalents, the liquidation of marketable securities and idle funds investments, and a combination of future debt and equity capital. Our primary uses of funds will be investments in portfolio companies, operating expenses and cash distributions to holders of our common stock.

We periodically invest excess cash balances into marketable securities and idle funds investments. The investment objective of marketable securities and idle funds investments is to generate incremental cash returns on excess cash balances prior to utilizing those funds for investment in our LMM and private placement portfolio investment strategy. Marketable securities and idle funds investments generally consist of debt investments, independently rated debt investments, certificates of deposit with financial institutions, and diversified bond funds. The composition of marketable securities and idle funds investments will vary in a given period based upon, among other things, changes in market conditions, the underlying fundamentals in our marketable securities and idle funds investments, our outlook regarding future LMM and private placement portfolio investment needs, and any regulatory requirements applicable to Main Street.

If our common stock trades below our net asset value per share, we will generally not be able to issue additional common stock at the market price unless our stockholders approve such a sale and our Board of Directors makes certain determinations. A proposal, approved by our stockholders at our June 2010 annual meeting of stockholders, authorizes us to sell shares of our common stock below the then current net asset value per share of our common stock in one or more offerings for a period of one year ending on June 9, 2011. We would need similar future approval from our stockholders to issue shares below the then current net asset value per share any time after the expiration of the current approval.

In order to satisfy the Code requirements applicable to a RIC, we intend to distribute to our stockholders substantially all of our taxable income, but we may also elect to periodically spillover certain excess undistributed taxable income from one tax year into the next tax year. In addition, as a BDC, we generally are required to meet a coverage ratio of total assets to total senior securities, which include borrowings and any preferred stock we may issue in the future, of at least 200%. This requirement limits the amount that we may borrow. In January 2008, we received exemptive relief from the SEC that permits us to exclude SBA-guaranteed debt issued by our wholly owned SBIC subsidiary, MSMF, from our asset coverage ratio, which, in turn, enables us to fund more investments with debt capital. We expect to obtain similar relief from the SEC with respect to SBIC debt securities issued by MSC II, including the $95 million of currently outstanding debt related to its participation in the SBIC program.

Although we have been able to secure access to additional liquidity, including our expanded $100 million Credit Facility, recent public stock offerings, and the increase in available leverage through the SBIC program as part of the Stimulus Bill, there is no assurance that debt or equity capital will be available to us in the future on favorable terms, or at all.

In June 2009, the Financial Accounting Standards Board ("FASB") issued ASC 810, Amendments to FASB Interpretation No. 46(R) ("ASC 810"), which amends the guidance in FASB Interpretation No. ("FIN") 46(R), Consolidation of Variable Interest Entities. It requires reporting entities to evaluate former qualifying special-purpose entities ("QSPEs") for consolidation, changes the approach to determining the primary beneficiary of a variable interest entity (a "VIE") from a quantitative assessment to a qualitative assessment designed to identify a controlling financial interest, and increases the frequency of required reassessments to determine whether a company is the primary beneficiary of a VIE. It also clarifies, but does not significantly change, the characteristics that identify a VIE. ASC 810 requires additional year-end and interim disclosures for public and non-public companies. ASC 810 is effective as of the beginning of a company's first fiscal year that begins

after November 15, 2009 and for subsequent interim and annual reporting periods. Main Street adopted ASC 810 on January 1, 2010. The FASB agreed at its January 27, 2010 meeting to issue an Accounting Standards Update ("ASU") to finalize its proposal to indefinitely defer ASC 810 for reporting enterprises' interests in entities that either have all of the characteristics of investment companies or for which it is industry practice to apply measurement principles for financial reporting purposes consistent with those that apply to investment companies. The provisions of ASC 810 will not have any impact on Main Street's financial condition or results of operations.

In January 2010, the FASB issued ASU 2010-06, Fair Value Measurements and Disclosures (Topic 820), Improving Disclosures About Fair Value Measurements ("ASU 2010-06"). ASU 2010-06 adds new requirements for disclosures about transfers into and out of Level 1 and 2 and separate disclosures about purchases, sales, issuances and settlements relating to Level 3 measurements. It also clarifies existing fair value disclosures about the level of disaggregation, inputs and valuation techniques. ASU 2010-06 is effective for interim and annual reporting periods beginning after December 15, 2009, except for the disclosures about purchases, sales, issuances and settlements in the roll forward of activity in Level 3 fair value measurements. Those disclosures are effective for fiscal years beginning after December 15, 2010. Adoption of ASU 2010-06 is not expected to have a significant impact on Main Street's financial condition and results of operations.

In December 2007, the FASB issued ASC 805, Business Combinations. Under ASC 805, an acquiring entity will be required to recognize all the assets acquired and liabilities assumed in a transaction at the acquisition-date fair value, with limited exceptions, replacing the previous cost-allocation process. ASC 805 also includes a substantial number of new disclosure requirements. ASC 805 is to be applied prospectively to business combinations for which the acquisition date is on or after the beginning of the first annual reporting period beginning on or after December 15, 2008. Early adoption is prohibited. Main Street adopted ASC 805 on January 1, 2009. Main Street accounted for the Exchange Offer under ASC 805 with the impact on the financial statements discussed in Note J to the consolidated financial statements.

Inflation has not had a significant effect on our results of operations in any of the reporting periods presented herein. However, our portfolio companies have experienced, and may in the future experience, the impacts of inflation on their operating results, including periodic escalations in their costs for raw materials and required energy consumption.

We may be a party to financial instruments with off-balance sheet risk in the normal course of business to meet the financial needs of our portfolio companies. These instruments include commitments to extend credit and involve, to varying degrees, elements of liquidity and credit risk in excess of the amount recognized in the balance sheet. At December 31, 2010, we had five outstanding commitments to fund unused revolving loans for up to $9.0 million in total.

As of December 31, 2010, our future fixed commitments for cash payments on contractual obligations for each of the next five years and thereafter are as follows:

MSC II is obligated to make payments under an investment advisory agreement with the Investment Manager, MSCC's wholly owned subsidiary. The payments due under the investment advisory agreement were fixed for the first five years at $3.3 million per year, paid quarterly, until September 30, 2010. Subsequent to September 30, 2010, under the investment advisory agreement, MSC II is obligated to pay a 2% annualized management fee based upon MSC II assets under management.

MSCC is obligated to make payments under a support services agreement with the Investment Manager. The Investment Manager is reimbursed for its excess cash expenses associated with providing investment management and other services to MSCC and its subsidiaries, as well as MSC II and third parties. Each quarter, as part of the support services agreement, MSCC makes payments to cover all cash expenses incurred by the Investment Manager, less the recurring management fees that the Investment Manager receives from MSC II pursuant to a long-term investment advisory services agreement and any other fees received from third parties for providing external services. For the years ended December 31, 2010 and 2009, the expenses reimbursed by MSCC to the Investment Manager were $2.2 million and $0.6 million, respectively.

As discussed further in Note D to the accompanying consolidated financial statements, subsequent to the completion of the Formation Transactions, the Investment Manager is a wholly owned portfolio company of MSCC. At December 31, 2010 and 2009, the Investment Manager had receivables of $15,124 and $217,422, respectively, due from MSCC related to net cash expenses incurred by the Investment Manager required to support Main Street's business.

We are subject to financial market risks, including changes in interest rates. Changes in interest rates may affect both our cost of funding and our interest income from portfolio investments, marketable securities, and

idle funds investments. Our risk management systems and procedures are designed to identify and analyze our risk, to set appropriate policies and limits and to continually monitor these risks. Our investment income will be affected by changes in various interest rates, including LIBOR and prime rates, to the extent of any debt investments that include floating interest rates. The majority of our debt investments are made with fixed interest rates for the term of the investment. However, as of December 31, 2010, approximately 26% of our debt investment portfolio (at cost) bore interest at floating rates with 96% of those floating-rate debt investments (at cost) subject to contractual minimum interest rates. Our interest expense will be affected by changes in the LIBOR rate in connection with our Credit Facility; however, the long term interest rates on our outstanding SBIC debentures, which comprise the majority of our outstanding debt, are fixed for the 10-year life of such debt. As of December 31, 2010, we had not entered into any interest rate hedging arrangements. At December 31, 2010, based on our applicable levels of floating-rate debt investments, a 1% change in interest rates would not have a material effect on our level of interest income from debt investments.

We have audited the accompanying consolidated balance sheets of Main Street Capital Corporation (a Maryland corporation), including the consolidated schedule of investments, as of December 31, 2010 and 2009 and the related consolidated statements of operations, changes in net assets and cash flows and the consolidated financial highlights (see Note H) for each of the three years in the period ended December 31, 2010. These financial statements and financial highlights are the responsibility of the Company's management. Our responsibility is to express an opinion on these financial statements and financial highlights based on our audits.

We conducted our audits in accordance with the standards of the Public Company Accounting Oversight Board (United States). Those standards require that we plan and perform the audits to obtain reasonable assurance about whether the financial statements are free of material misstatement. An audit also includes examining, on a test basis, evidence supporting the amounts and disclosures in the financial statements. Our procedures included verification by examination of securities held by the custodian as of December 31, 2010 and 2009, and confirmation of securities not held by the custodian. An audit also includes assessing the accounting principles used and significant estimates made by management, as well as evaluating the overall financial statement presentation. We believe that our audits provide a reasonable basis for our opinion.

In our opinion, the consolidated financial statements and financial highlights referred to above present fairly, in all material respects, the consolidated financial position of Main Street Capital Corporation as of December 31, 2010 and 2009 and the consolidated results of their operations, changes in net assets, cash flows and financial highlights for each of the three years in the period ended December 31, 2010, in conformity with accounting principles generally accepted in the United States of America.

We also have audited, in accordance with the standards of the Public Company Accounting Oversight Board (United States), Main Street Capital Corporation's internal control over financial reporting as of December 31, 2010, based on criteria established in Internal Control — Integrated Framework issued by the Committee of Sponsoring Organizations of the Treadway Commission (COSO), and our report dated March 11, 2011, expressed an unqualified opinion on the effectiveness of the Company's internal control over financial reporting.

We have audited Main Street Capital Corporation's (a Maryland corporation) (the Company) internal control over financial reporting as of December 31, 2010, based on criteria established in Internal Control — Integrated Framework issued by the Committee of Sponsoring Organizations of the Treadway Commission (COSO). Main Street Capital Corporation's management is responsible for maintaining effective internal control over financial reporting and for its assessment of the effectiveness of internal control over financial reporting, included in the accompanying Management's Report on Internal Control over Financial Reporting. Our responsibility is to express an opinion on Main Street Capital Corporation's internal control over financial reporting based on our audit.

We conducted our audit in accordance with the standards of the Public Company Accounting Oversight Board (United States). Those standards require that we plan and perform the audit to obtain reasonable assurance about whether effective internal control over financial reporting was maintained in all material respects. Our audit included obtaining an understanding of internal control over financial reporting, assessing the risk that a material weakness exists, and testing and evaluating the design and operating effectiveness of internal control based on the assessed risk, and performing such other procedures as we considered necessary in the circumstances. We believe that our audit provides a reasonable basis for our opinion.

A company's internal control over financial reporting is a process designed to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements for external purposes in accordance with generally accepted accounting principles. A company's internal control over financial reporting includes those policies and procedures that (1) pertain to the maintenance of records that, in reasonable detail, accurately and fairly reflect the transactions and dispositions of the assets of the company; (2) provide reasonable assurance that transactions are recorded as necessary to permit preparation of financial statements in accordance with generally accepted accounting principles, and that receipts and expenditures of the company are being made only in accordance with authorizations of management and directors of the company; and (3) provide reasonable assurance regarding prevention or timely detection of unauthorized acquisition, use, or disposition of the company's assets that could have a material effect on the financial statements.

Because of its inherent limitations, internal control over financial reporting may not prevent or detect misstatements. Also, projections of any evaluation of effectiveness to future periods are subject to the risk that controls may become inadequate because of changes in conditions, or that the degree of compliance with the policies or procedures may deteriorate.

In our opinion, Main Street Capital Corporation maintained, in all material respects, effective internal control over financial reporting as of December 31, 2010, based on criteria established in Internal Control — Integrated Framework issued by COSO.

We also have audited, in accordance with the standards of the Public Company Accounting Oversight Board (United States), the consolidated balance sheets of Main Street Capital Corporation as of December 31, 2010 and 2009, including the consolidated schedule of investments as of December 31, 2010 and 2009, and the related consolidated statements of operations, changes in net assets and cash flows, and the financial highlights (see Note H), for each of the three years in the period ended December 31, 2010, and our report dated March 11, 2011, expressed an unqualified opinion.

			December 31, 2010			December 31, 2009

ASSETS
Portfolio investments at fair value:
	Control investments (cost: $161,009,443 and $59,544,719 as of December 31, 2010 and 2009, respectively)		$	174,596,394		$	66,400,667
	Affiliate investments (cost: $65,650,789 and $39,252,445 as of December 31, 2010 and 2009, respectively)			80,206,804			46,886,202
	Non-Control/Non-Affiliate investments (cost: $91,911,304 and $27,482,826 as of December 31, 2010 and 2009, respectively)			91,956,221			27,416,287
	Investment in affiliated Investment Manager (cost: $4,284,042 and $18,000,000 as of December 31, 2010 and 2009, respectively)			2,051,655			16,036,838

		Total portfolio investments (cost: $322,855,578 and $144,279,990 as of December 31, 2010 and 2009, respectively)		348,811,074			156,739,994
Marketable securities and idle funds investments (cost: $67,970,907 and $3,252,954 as of December 31, 2010 and 2009, respectively)				68,752,858			3,252,954

		Total investments (cost: $390,826,485 and $147,532,944 as of December 31, 2010 and 2009, respectively)		417,563,932			159,992,948
Cash and cash equivalents				22,334,340			30,619,998
Deferred tax asset				1,958,593			2,716,400
Interest receivable and other assets				4,523,792			1,509,608
Deferred financing costs (net of accumulated amortization of $1,504,584 and $1,071,676 as of December 31, 2010 and 2009, respectively)				2,543,645			1,611,508

		Total assets	$	448,924,302		$	196,450,462

LIABILITIES
	SBIC debentures (par: $180,000,000 and $65,000,000 as of December 31, 2010 and 2009, respectively; of which $70,557,975 is recorded at fair value as of December 31, 2010)		$	155,557,975		$	65,000,000
	Credit facility			39,000,000			—
	Interest payable			3,194,870			1,069,148
	Payable to affiliated Investment Manager			15,124			217,422
	Accounts payable and other liabilities			1,173,295			503,761

		Total liabilities		198,941,264			66,790,331
Commitments and contingencies
NET ASSETS
Common stock, $0.01 par value per share (150,000,000 shares authorized; 18,797,444 and 10,842,447 issued and outstanding as of December 31, 2010 and 2009, respectively)				187,975			108,425
Additional paid-in capital				224,485,165			123,534,156
Accumulated net investment income				9,261,405			7,269,866
Accumulated net realized gain (loss) from investments				(20,541,897	)		(15,922,020	)
Net unrealized appreciation, net of income taxes				32,141,997			14,669,704

		Total Net Asset Value		245,534,645			129,660,131
Noncontrolling interest				4,448,393			—

		Total net assets including noncontrolling interests		249,983,038			129,660,131

		Total liabilities and net assets	$	448,924,302		$	196,450,462

NET ASSET VALUE PER SHARE			$	13.06		$	11.96

				Years Ended December 31,

				2010			2009			2008
INVESTMENT INCOME:
	Interest, fee and dividend income:
		Control investments		$	17,526,766		$	8,022,687		$	9,826,369
		Affiliate investments			8,250,622			4,581,295			4,842,442
		Non-Control/Non-Affiliate investments			7,747,739			1,678,962			1,454,718

	Total interest, fee and dividend income				33,525,127			14,282,944			16,123,529
	Interest from marketable securities, idle funds and other				2,982,780			1,719,303			1,171,897

			Total investment income		36,507,907			16,002,247			17,295,426
EXPENSES:
	Interest				(9,058,386	)		(3,790,702	)		(3,777,919	)
	General and administrative				(1,437,027	)		(1,351,451	)		(1,684,084	)
	Expenses reimbursed to affiliated Investment Manager				(5,263,133	)		(569,868	)		(1,006,835	)
	Share-based compensation				(1,488,709	)		(1,068,397	)		(511,452	)

			Total expenses		(17,247,255	)		(6,780,418	)		(6,980,290	)

NET INVESTMENT INCOME					19,260,652			9,221,829			10,315,136
NET REALIZED GAIN (LOSS) FROM INVESTMENTS:
	Control investments				(3,587,638	)		(3,441,483	)		188,214
	Affiliate investments				—			(5,055,796	)		1,209,280
	Non-Control/Non-Affiliate investments				235			70,628			—
	Marketable securities and idle funds investments				707,740			629,103			—

			Total net realized gain (loss) from investments		(2,879,663	)		(7,797,548	)		1,397,494

NET REALIZED INCOME					16,380,989			1,424,281			11,712,630
NET CHANGE IN UNREALIZED APPRECIATION (DEPRECIATION):
	Portfolio investments				12,264,717			9,051,986			(3,182,809	)
	Marketable securities and idle funds investments				781,951			(171,091	)		171,091
	SBIC debentures				6,861,971			—			—
	Investment in affiliated Investment Manager				(269,225	)		(638,788	)		(949,374	)

			Total net change in unrealized appreciation (depreciation)		19,639,414			8,242,107			(3,961,092	)

	Income tax (provision) benefit				(940,634	)		2,289,841			3,182,401
	Bargain purchase gain				4,890,582			—			—

NET INCREASE IN NET ASSETS RESULTING FROM OPERATIONS					39,970,351			11,956,229			10,933,939
	Noncontrolling interest				(1,226,487	)		—			—

NET INCREASE IN NET ASSETS RESULTING FROM OPERATIONS ATTRIBUTABLE TO COMMON STOCK				$	38,743,864		$	11,956,229		$	10,933,939

NET INVESTMENT INCOME PER SHARE — BASIC AND DILUTED				$	1.16		$	0.92		$	1.13

NET REALIZED INCOME PER SHARE — BASIC AND DILUTED				$	0.99		$	0.14		$	1.29

NET INCREASE IN NET ASSETS RESULTING FROM OPERATIONS ATTRIBUTABLE TO COMMON STOCK PER SHARE — BASIC AND DILUTED				$	2.38		$	1.19		$	1.20

DIVIDENDS PAID PER SHARE				$	1.50		$	1.50		$	1.43

WEIGHTED AVERAGE SHARES OUTSTANDING — BASIC AND DILUTED					16,292,846			10,042,639			9,095,904

	Common Stock																								Total Net Assets Including Noncontrolling Interest

	Common Stock												Accumulated Net Realized Gain (Loss) From Investments			Net Unrealized Appreciation, Net of Income Taxes
	Number of Shares			Par Value			Additional Paid-In Capital			Accumulated Net Investment Income			Accumulated Net Realized Gain (Loss) From Investments			Net Unrealized Appreciation, Net of Income Taxes			Total Net Asset Value			Noncontrolling Interest
Balances at December 31, 2007		8,959,718		$	89,597		$	104,076,033		$	6,067,131		$	—		$	4,916,447		$	115,149,208		$	—		$	115,149,208
Dividend reinvestment		15,820			158			213,571			—			—			—			213,729			—			213,729
Share repurchase program		(34,700	)		(347	)		(330,659	)		—			—			—			(331,006	)		—			(331,006	)
Issuance of restricted stock, net of forfeitures		265,645			2,657			(2,657	)		—			—			—			—			—			—
Share-based compensation		—			—			511,452			—			—			—			511,452			—			511,452
Dividends to stockholders		—			—			—			(6,226,674	)		(7,894,592	)		—			(14,121,266	)		—			(14,121,266	)
Net increase resulting from operations		—			—			—			10,315,136			1,397,494			(778,691	)		10,933,939			—			10,933,939

Balances at December 31, 2008		9,206,483			92,065			104,467,740			10,155,593			(6,497,098	)		4,137,756			112,356,056			—			112,356,056
Public offering of common stock, net of offering costs		1,437,500			14,375			16,176,533			—			—			—			16,190,908			—			16,190,908
Share-based compensation		—			—			1,068,397			—			—			—			1,068,397			—			1,068,397
Dividend reinvestment		271,906			2,719			3,690,001			—			—			—			3,692,720			—			3,692,720
Share repurchase program		(164,544	)		(1,645	)		(1,615,461	)		—			—			—			(1,617,106	)		—			(1,617,106	)
Issuance of restricted stock		107,505			1,075			(1,075	)		—			—			—			—			—			—
Purchase of vested stock for employee payroll tax withholding		(16,403	)		(164	)		(251,979	)		—			—			—			(252,143	)		—			(252,143	)
Dividends to stockholders		—			—			—			(12,107,556	)		(1,627,374	)		—			(13,734,930	)		—			(13,734,930	)
Net increase resulting from operations		—			—			—			9,221,829			(7,797,548	)		10,531,948			11,956,229			—			11,956,229

Balances at December 31, 2009		10,842,447			108,425			123,534,156			7,269,866			(15,922,020	)		14,669,704			129,660,131			—			129,660,131
MSC II exchange offer and related transactions		1,246,803			12,468			20,080,623			4,890,582			—			—			24,983,673			3,237,210			28,220,883
Public offerings of common stock, net of offering costs		6,095,000			60,950			85,836,250			—			—			—			85,897,200			—			85,897,200
Share-based compensation		—			—			1,488,709			—			—			—			1,488,709			—			1,488,709
Dividend reinvestment		478,731			4,787			7,632,303			—			—			—			7,637,090			—			7,637,090
Issuance of restricted stock		157,277			1,573			(1,573	)		—			—			—			—			—			—
Purchase of vested stock for employee payroll tax withholding		(22,814	)		(228	)		(369,345	)		—			—			—			(369,573	)		—			(369,573	)
Adjustment to investment in Investment Manager related to the MSC II Exchange Offer		—			—			(13,715,958	)		—			—			—			(13,715,958	)		—			(13,715,958	)
Distributions to noncontrolling interest		—			—			—			—			—			—			—			(15,304	)		(15,304	)
Dividends to stockholders		—			—			—			(22,159,695	)		(1,740,214	)		—			(23,899,909	)		—			(23,899,909	)
Net increase resulting from operations		—			—			—			19,260,652			(2,879,663	)		18,698,780			35,079,769			—			35,079,769
Noncontrolling interest		—			—			—			—			—			(1,226,487	)		(1,226,487	)		1,226,487			—

Balances at December 31, 2010		18,797,444		$	187,975		$	224,485,165		$	9,261,405		$	(20,541,897	)	$	32,141,997		$	245,534,645		$	4,448,393		$	249,983,038

					Years Ended December 31,

					2010			2009			2008
CASH FLOWS FROM OPERATING ACTIVITIES
	Net increase in net assets resulting from operations:				$	39,970,351		$	11,956,229		$	10,933,939
	Adjustments to reconcile net increase in net assets resulting from operations to net cash provided by operating activities:
		Net change in unrealized (appreciation) depreciation				(19,639,414	)		(8,242,107	)		3,961,092
		Net realized (gain) loss from investments				2,879,663			7,797,548			(1,397,494	)
		Bargain purchase gain				(4,890,582	)		—			—
		Accretion of unearned income				(2,790,394	)		(701,956	)		(1,062,452	)
		Net payment-in-kind interest accrual				(2,589,029	)		(655,762	)		(216,505	)
		Share-based compensation expense				1,488,709			1,068,397			511,452
		Amortization of deferred financing costs				470,012			414,545			426,084
		Deferred taxes				674,980			(1,594,719	)		(4,147,353	)
		Fees and other				2,068,179			(578,404	)		612,143
		Changes in other assets and liabilities:
			Interest receivable and other assets			(1,961,515	)		(359,312	)		115,533
			Interest payable			782,624			(39,045	)		45,521
			Payable to affiliated Investment Manager			(202,298	)		(85,212	)		302,633
			Accounts payable and other liabilities			343,024			(935,595	)		828,098

				Net cash provided by operating activities		16,604,310			8,044,607			10,912,691
CASH FLOWS FROM INVESTING ACTIVITIES
	Investments in portfolio companies					(157,689,915	)		(24,741,598	)		(47,698,567	)
	Cash acquired in MSC II exchange offer					2,489,920			—			—
	Investments in marketable securities and idle funds investments					(100,563,154	)		(85,855,676	)		(4,218,704	)
	Proceeds from marketable securities and idle funds investments					36,754,208			73,513,104			24,063,261
	Principal payments received on loans and debt securities					39,815,482			11,121,773			16,300,750
	Proceeds from sale of equity securities and related notes					3,175,283			—			8,029,339

				Net cash provided by (used in) investing activities		(176,018,176	)		(25,962,397	)		(3,523,921	)
CASH FLOWS FROM FINANCING ACTIVITIES
	Share repurchase program					—			(1,617,106	)		(331,006	)
	Proceeds from public offering of common stock, net of offering costs					85,897,200			16,190,908			—
	Distributions to noncontrolling interest					(15,304	)		—			—
	Dividends paid to stockholders					(16,262,819	)		(11,167,882	)		(12,781,074	)
	Net change in DRIP deposit					—			400,000			(400,000	)
	Proceeds from issuance of SBIC debentures					45,000,000			10,000,000			—
	Proceeds from credit facility					75,650,000			—			—
	Repayments on credit facility					(36,650,000	)		—			—
	Purchase of vested stock for employee payroll tax withholding					(369,573	)		(252,143	)		—
	Payment of deferred loan costs and SBIC debenture fees					(2,121,296	)		(390,815	)		(391,188	)

				Net cash provided by (used in) financing activities		151,128,208			13,162,962			(13,903,268	)

Net increase (decrease) in cash and cash equivalents						(8,285,658	)		(4,754,828	)		(6,514,498	)
CASH AND CASH EQUIVALENTS AT BEGINNING OF PERIOD						30,619,998			35,374,826			41,889,324

CASH AND CASH EQUIVALENTS AT END OF PERIOD					$	22,334,340		$	30,619,998		$	35,374,826

Portfolio Company/Type of Investment(1)(2)			Industry

Control Investments(3)
	Café Brazil, LLC		Casual Restaurant
		12% Secured Debt (Maturity — April 20, 2013)	Group	2,000,000	1,997,439	2,000,000
		Member Units(7) (Fully diluted 41.0%)			41,837	2,240,000

					2,039,276	4,240,000
	California Healthcare Medical Billing, Inc.		Healthcare Billing and
		12% Secured Debt (Maturity — October 17, 2013)	Records Management	7,303,000	6,937,251	6,985,748
		Warrants (Fully diluted 20.4%)			1,193,333	3,380,333
		Common Stock (Fully diluted 9.7%)			1,176,667	1,390,000

					9,307,251	11,756,081
	CBT Nuggets, LLC		Produces and Sells IT
		10% Secured Debt (Maturity — March 31, 2012)	Certification Training	775,000	775,000	775,000
		14% Secured Debt (Maturity — December 31, 2013)	Videos	2,800,000	2,787,551	2,792,180
		Member Units(7) (Fully diluted 40.8%)			1,299,520	3,450,000

					4,862,071	7,017,180
	Ceres Management, LLC (Lambs)		Aftermarket Automotive
		14% Secured Debt (Maturity — May 31, 2013)	Services Chain	4,000,000	3,964,568	3,964,568
		9.5% Secured Debt (Lamb's Real Estate Investment I, LLC) (Maturity — August 31, 2014)		1,225,000	1,225,000	1,225,000
		Class B Member Units (15% cumulative compounding quarterly) (Non-voting)			1,508,611	1,508,611
		Member Units (Fully diluted 70%)			1,813,333	1,100,000
		Member Units(7) (Lamb's Real Estate Investment I, LLC) (Fully diluted 100%)			625,000	625,000

					9,136,512	8,423,179
	Condit Exhibits, LLC		Tradeshow Exhibits/
		9% current / 9% PIK Secured Debt (Maturity — July 1, 2013)	Custom Displays	4,660,948	4,619,659	4,619,659
		Warrants (Fully diluted 47.9%)			320,000	50,000

					4,939,659	4,669,659
	Currie Acquisitions, LLC		Manufacturer of Electric
		12% Secured Debt (Maturity — March 1, 2015)	Bicycles/Scooters	4,750,000	3,971,699	3,971,699
		Warrants (Fully diluted 47.3%)			2,566,204	2,340,204

					6,537,903	6,311,903
	Gulf Manufacturing, LLC		Industrial Metal Fabrication
		8% Secured Debt (Maturity — August 31, 2014)		3,620,000	3,620,000	3,620,000
		13% Secured Debt (Maturity — August 31, 2012)		1,680,000	1,649,959	1,675,165
		9% PIK Secured Debt (Maturity — June 30, 2017)		1,420,784	1,420,784	1,420,784
		Member Units(7) (Fully diluted 34.2%)			2,979,813	5,870,000

					9,670,556	12,585,949
	Harrison Hydra-Gen, Ltd.		Manufacturer of Hydraulic
		12% Secured Debt (Maturity — June 4, 2015)	Generators	6,000,000	5,255,101	5,255,101
		Warrants (Fully diluted 35.2%)			717,640	717,640
		Mandatorily Redeemable Preferred Stock			1,000,000	1,000,000

					6,972,741	6,972,741

Portfolio Company/Type of Investment(1)(2)			Industry

Control Investments(3)
	Hawthorne Customs & Dispatch Services, LLC		Transportation/ Logistics
		Member Units(7) (Fully diluted 59.1%)			692,500	1,250,000
		Member Units (Wallisville Real Estate, LLC)(7) (Fully diluted 59.1%)			1,214,784	1,214,784

					1,907,284	2,464,784
	Hydratec, Inc.		Agricultural Services
		Common Stock (Fully diluted 92.5%)(7)			7,087,911	9,177,911

	Indianapolis Aviation Partners, LLC		FBO / Aviation
		12% Secured Debt (Maturity — September 15, 2014)	Support Services	4,500,000	4,140,255	4,350,000
		Warrants (Fully diluted 30.1%)			1,129,286	1,570,286

					5,269,541	5,920,286
	Jensen Jewelers of Idaho, LLC		Retail Jewelry
		Prime Plus 2% Secured Debt (Maturity — November 14, 2011)		2,260,000	2,256,486	2,260,000
		13% current / 6% PIK Secured Debt (Maturity — November 14, 2011)		2,344,897	2,340,040	2,344,896
		Member Units(7) (Fully diluted 60.8%)			811,000	1,060,000

					5,407,526	5,664,896
	Mid-Columbia Lumber Products, LLC		Specialized Lumber
		10% Secured Debt (Maturity — April 1, 2012)	Products	1,250,000	1,250,000	1,250,000
		12% Secured Debt (Maturity — December 18, 2011)		3,900,000	3,803,664	3,900,000
		9.5% Secured Debt (Mid — Columbia Real Estate, LLC) (Maturity — May 13, 2025)		1,107,400	1,107,400	1,107,400
		Warrants (Fully diluted 25.5%)			250,000	740,000
		Member Units (Fully diluted 26.7%)			500,000	770,000
		Member Units (Mid — Columbia Real Estate, LLC) (Fully diluted 50.0%)			250,000	250,000

					7,161,064	8,017,400
	NAPCO Precast, LLC		Precast Concrete
		18% Secured Debt (Maturity — February 1, 2013)	Manufacturing	5,923,077	5,860,313	5,923,077
		Prime Plus 2% Secured Debt (Maturity — February 1, 2013)(8)		3,384,615	3,368,600	3,384,615
		Member Units(7) (Fully diluted 35.3%)			2,020,000	4,340,000

					11,248,913	13,647,692
	NTS Holdings, Inc.		Trench & Traffic Safety
		12% Secured Debt (Maturity — April 30, 2015)	Equipment	6,000,000	5,963,931	5,963,931
		Preferred stock (12% cumulative, compounded quarterly)			10,635,273	10,635,273
		Common Stock (Fully diluted 72.3%)			1,621,255	776,000

					18,220,459	17,375,204
	OMi Holdings, Inc.		Manufacturer of Overhead
		12% Secured Debt (Maturity — April 1, 2013)	Cranes	10,170,000	10,116,824	10,116,824
		Common Stock (Fully diluted 48.0%)			1,080,000	500,000

					11,196,824	10,616,824

Portfolio Company/Type of Investment(1)(2)			Industry

Control Investments(3)
	PPL RVs, Inc.		RV Aftermarket
		18% Secured Debt (Maturity — June 10, 2015)	Consignment/Parts	6,250,000	6,165,058	6,165,058
		Common Stock (Fully diluted 50.1%)			2,150,000	2,150,000

					8,315,058	8,315,058
	The MPI Group, LLC		Manufacturer of Custom
		4.5% current / 4.5% PIK Secured Debt (Maturity — October 2, 2013)	Hollow Metal Doors, Frames and Accessories	507,625	501,176	501,176
		6% current / 6% PIK Secured Debt (Maturity — October 2, 2013)		5,101,667	4,935,760	4,935,760
		Warrants (Fully diluted 47.1%)			895,943	190,000

					6,332,879	5,626,936
	Thermal & Mechanical Equipment, LLC		Heat Exchange / Filtration
		Prime plus 2% Secured Debt (Maturity — September 25, 2014)(8)	Products and Services	1,750,000	1,739,152	1,739,152
		13% current / 5% PIK Secured Debt (Maturity — September 25, 2014)		5,575,220	5,501,111	5,575,220
		Warrants (Fully diluted 50.0%)			1,000,000	1,940,000

					8,240,263	9,254,372
	Uvalco Supply, LLC		Farm and Ranch Supply
		Member Units (Fully diluted 42.8%)(7)			1,113,243	1,560,000

	Vision Interests, Inc.		Manufacturer/Installer of
		2.6% current /10.4% PIK Secured Debt (Maturity — June 5, 2012)	Commercial Signage	9,400,000	8,424,811	8,022,651
		2.6% current /10.4% PIK Secured Debt (Maturity — June 5, 2016)		760,000	739,663	739,663
		Warrants (Fully diluted 38.2%)			160,010	—
		Common Stock (Fully diluted 22.3%)			372,000	—

					9,696,484	8,762,314
	Ziegler's NYPD, LLC		Casual Restaurant Group
		Prime plus 2% Secured Debt (Maturity — October 1, 2013)(8)		1,000,000	993,937	993,937
		13% current / 5% PIK Secured Debt (Maturity — October 1, 2013)		4,801,810	4,752,088	4,752,088
		Warrants (Fully diluted 46.6%)			600,000	470,000

					6,346,025	6,216,025

	Subtotal Control Investments				161,009,443	174,596,394

Portfolio Company/Type of Investment(1)(2)			Industry

Affiliate Investments(4)
	American Sensor Technologies, Inc.		Manufacturer of
		9% current / 2% PIK Secured Debt (Maturity — May 31, 2012)	Commercial/Industrial Sensors	3,536,182	3,514,113	3,514,113
		Warrants (Fully diluted 19.6%)			49,990	1,830,000

					3,564,103	5,344,113
	Audio Messaging Solutions, LLC		Audio Messaging Services
		12% Secured Debt (Maturity — May 8, 2014)		7,700,000	7,356,395	7,426,299
		Warrants (Fully diluted 8.4%)			468,373	1,280,000

					7,824,768	8,706,299
	Compact Power Equipment Centers, LLC		Light to Medium Duty
		6% Current / 6% PIK Secured Debt (Maturity — September 23, 2014)	Equipment Rental	3,153,971	3,120,950	3,120,950
		Member Units (Fully diluted 11.5%)			1,147	1,147

					3,122,097	3,122,097
	DrillingInfo, Inc.		Information Services for
		12% Secured Debt (Maturity — November 20, 2014)	the Oil and Gas Industry	8,000,000	6,832,370	7,770,000
		Warrants (Fully diluted 5.0%)			1,250,000	4,010,000
		Common Stock (Fully diluted 2.1%)			1,085,325	1,710,325

					9,167,695	13,490,325
	East Teak Fine Hardwoods, Inc.		Hardwood Products
		Common Stock (Fully diluted 5.0%)			480,318	330,000

	Houston Plating & Coatings, LLC		Plating & Industrial
		Prime plus 2% Debt (Maturity — July 18, 2013)	Coating Services	300,000	300,000	300,000
		Member Units(7) (Fully diluted 11.1%)			335,000	3,025,000

					635,000	3,325,000
	IRTH Holdings, LLC		Utility Technology
		12% Secured Debt (Maturity — December 29, 2015)	Services	6,000,000	5,891,126	5,891,126
		Member Units (Fully diluted 22.3%)			850,000	850,000

					6,741,126	6,741,126
	KBK Industries, LLC		Specialty Manufacturer of
		10% Secured Debt (Maturity — March 31, 2011)	Products	514,940	514,940	514,940
		14% Secured Debt (Maturity — January 23, 2011)	Oilfield and Industrial	5,250,000	5,241,999	5,241,999
		Member Units(7) (Fully diluted 18.8%)			340,833	1,790,333

					6,097,772	7,547,272
	Laurus Healthcare, LP		Healthcare Facilities /
		13% Secured Debt (Maturity — May 7, 2012)	Services	2,275,000	2,275,000	2,275,000
		13% Secured Debt (Maturity — December 31, 2011)		525,000	525,000	525,000
		Warrants (Fully diluted 13.1%)			79,505	4,620,000

					2,879,505	7,420,000
	Lighting Unlimited, LLC		Commercial and Residential
		Prime Plus 1% Secured Debt (Maturity — August 22, 2012)(8)	Lighting Products and Design Services	949,996	946,598	946,598
		14% Secured Debt (Maturity — August 22, 2012)		1,760,101	1,723,326	1,723,326
		Warrants (Fully diluted 17.0%)			54,000	—

					2,723,924	2,669,924

Portfolio Company/Type of Investment(1)(2)			Industry

Affiliate Investments(4)
	Merrick Systems, Inc.		Software and
		13% Secured Debt (Maturity — May 5, 2015)	Information	3,000,000	2,540,849	2,540,849
		Warrants (Fully diluted 6.5%)	Technology		450,000	450,000

					2,990,849	2,990,849
	Olympus Building Services, Inc.		Custodial/Facilities
		12% Secured Debt (Maturity — March 27, 2014)	Services	3,150,000	2,976,408	3,050,000
		12% Current / 3% PIK Secured Debt (Maturity — March 27, 2014)		984,000	984,001	984,001
		Warrants (Fully diluted 22.5%)			470,000	930,000

					4,430,409	4,964,001
	OPI International Ltd.		Oil and Gas
		12% Secured Debt (Maturity — November 30, 2015)	Construction Services	8,700,000	8,537,285	8,537,285
		12% Secured Debt (Maturity — November 30, 2015)		750,000	252,288	252,288
		Warrants (Fully diluted 8.0%)			500,000	500,000

					9,289,573	9,289,573
	Schneider Sales Management, LLC		Sales Consulting and
		13% Secured Debt (Maturity — October 15, 2013)	Training	3,367,542	3,289,127	1,000,000
		Warrants (Fully diluted 20.0%)			45,000	—

					3,334,127	1,000,000
	Walden Smokey Point, Inc.		Specialty Transportation/
		Common Stock (Fully diluted 12.6%)			1,426,667	2,620,000

	WorldCall, Inc.		Telecommunication/
		13% Secured Debt (Maturity — April 22, 2011)	Information Services	646,225	646,225	646,225
		Common Stock (Fully diluted 10.0%)			296,631	—

					942,856	646,225

	Subtotal Affiliate Investments				65,650,789	80,206,804

Portfolio Company/Type of Investment(1)(2)			Industry

Non-Control/Non-Affiliate Investments(5):
	Affinity Videonet, Inc.		Videoconferencing Services
		9% Secured Debt (Maturity — December 31, 2012)		500,000	490,000	490,000
		13% Secured Debt (Maturity — December 31, 2015)		2,000,000	1,897,500	1,897,500
		13% current / 1% PIK Secured Debt (Maturity — December 31, 2015)		2,000,000	1,995,652	1,995,652
		Warrants (Fully diluted 2.5%)			62,500	62,500

					4,445,652	4,445,652
	Alon Refining Krotz Springs, Inc.(9)		Petroleum Products/
		13.5% Secured Debt (Maturity — October 15, 2014)	Refining	4,000,000	3,832,366	3,900,000

	Bourland & Leverich Supply Co., LLC(9)		Distributor of Oil & Gas
		LIBOR Plus 8.0% Secured Debt (Maturity — August 24, 2015)(8)	Tubular Goods	4,443,750	4,236,574	4,554,847

	Brand Connections, LLC		Venue-Based
		14% Secured Debt (Maturity — April 30, 2015)	Marketing and Media	7,312,500	7,151,303	7,151,303

	Chef's Warehouse(9)		Specialty Food
		LIBOR Plus 9.0% Secured Debt (Maturity — April 24, 2014)(8)	Distributor	8,137,083	7,907,586	8,219,225

	Fairway Group Acquisition(9)		Retail Grocery
		LIBOR plus 9.5% Secured Debt (Maturity — October 1, 2014)(8)		4,950,008	4,827,316	4,968,818

	Full Spectrum Holdings LLC(9)		Professional Services
		LIBOR Plus 3.0% Secured Debt (Maturity — December 12, 2012)(8)		1,523,341	1,301,663	1,301,663
		Warrants (Fully diluted 0.28%)			412,523	412,523

					1,714,186	1,714,186
	*Global TelLink Corporation(9)**		Communiations
		LIBOR Plus 11.25% Secured Debt (Maturity — May 10, 2017)(8)	Technology	3,000,000	2,941,728	2,948,271

	Hayden Acquisition, LLC		Manufacturer of Utility
		8% Secured Debt (Maturity — January 1, 2011)	Structures	1,800,000	1,781,303	250,000

	Hoffmaster Group, Inc.(9)		Manufacturer of Specialty
		13.5% Secured Debt (Maturity — June 3, 2017)	Tabletop Products	5,000,000	4,881,278	4,787,500
		LIBOR Plus 5.0% Secured Debt (Maturity — June 13, 2016)(8)		1,509,615	1,453,860	1,490,745

					6,335,138	6,278,245
	Managed Healthcare(9)		Healthcare Products
		LIBOR plus 3.25% Secured Debt (Maturity — August 31, 2014)(8)		1,987,606	1,548,214	1,659,650

	Megapath Inc.(9)		Communiations
		LIBOR plus 10% Secured Debt (Maturity — November 4, 2015)(8)	Technology	4,000,000	3,922,670	4,040,770

Portfolio Company/Type of Investment(1)(2)			Industry		Cost(6)		Fair Value

Non-Control/Non-Affiliate Investments(5):
	Miramax Film NY, LLC(9)		Motion Picture Producer
		LIBOR plus 6% Secured Debt (Maturity — June 30, 2016)(8)	and Distributor	3,000,000		2,940,000		2,940,000
		LIBOR plus 11% Secured Debt (Maturity — December 30, 2016)(8)		4,000,000		3,920,000		3,920,000
		Class B Units (Fully diluted 0.2%)				500,000		500,000

						7,360,000		7,360,000
	Northland Cable Television, Inc.(9)		Cable Broadcasting
		LIBOR Plus 8.0% Secured Debt (Maturity — June 22, 2013)(8)		5,000,000		4,851,285		4,988,785

	Pierre Foods, Inc.(9)		Foodservice Supplier
		Base plus 4.25% Secured Debt (Maturity — September 30, 2016)(8)		5,000,000		4,903,804		4,992,702
		Base plus 8.5% Secured Debt (Maturity — September 29, 2017)(8)		2,000,000		1,932,106		1,992,181

						6,835,910		6,984,883
	Rentech Energy Midwest Corporation(9)		Manufacturer of Fertilizer
		LIBOR plus 10% Secured Debt (Maturity — July 29, 2014)(8)		2,331,606		2,274,262		2,274,262

	Shearer's Foods, Inc.(9)		Manufacturer of Food /
		12% Current / 3% PIK Secured Debt (Maturity — March 21, 2016)(8)	Snacks	4,092,707		3,999,396		4,154,098

	Standard Steel, LLC(9)		Manufacturer of Steel
		12% Secured Debt (Maturity — April 30, 2015)	Wheels and Axles	3,000,000		2,902,821		2,988,750

	Support Systems Homes, Inc.		Manages Substance Abuse
	15% Secured Debt (Maturity — August 21, 2018)		Treatment Centers	576,600		576,600		576,600

	Technical Innovations, LLC		Manufacturer of Specialty
	13.5% Secured Debt (Maturity — January 16, 2015)		Cutting Tools and Punches	2,950,000		2,919,118		2,950,000

	The Tennis Channel, Inc.		Sports Broadcasting/
		LIBOR plus 6% / 4% PIK Secured Debt (Maturity — January 1, 2013)(8)	Media	9,198,840		9,230,938		9,230,938
		Warrants (Fully diluted 0.10%)				211,938		211,938

						9,442,876		9,442,876
	Other(10)					105,000		105,000

	Subtotal Non-Control/Non-Affiliate Investments					91,911,304		91,956,221

	Main Street Capital Partners, LLC (Investment Manager)		Asset Management
	100% of Membership Interests					4,284,042		2,051,655

	Total Portfolio Investments, December 31, 2010				$	322,855,578	$	348,811,074

Portfolio Company/Type of Investment(1)(2)			Industry	Principal(6)		Cost(6)		Fair Value

Marketable Securities and Idle Funds Investments			Investments in Secured and
	AL Gulf Coast Terminals, LLC		Rated Debt Investments,
		LIBOR plus 5.0% Secured Debt (Maturity — September 21, 2016)(8)	Certificates of Deposit, and Diversified Bond Funds	$	6,919,997	$	6,735,294	$	6,746,997
	Aspen Dental Management, Inc.
		LIBOR plus 5.0% Secured Debt (Maturity — October 13, 2016)(8)			4,987,500		4,691,670		4,806,974
	ATI Acquisition I Corp.
		LIBOR plus 5.5% Secured Debt (Maturity — September 14, 2016)(8)			2,885,675		2,841,517		2,857,332
	Booz Allen Hamilton Inc.
		13% Debt (Maturity — July 5, 2016)(8)			1,716,044		1,781,625		1,765,380
	Centerplate, Inc.
		LIBOR plus 7.5% Secured Debt (Maturity — September 16, 2016)(8)			3,000,000		2,914,206		2,988,750
	CHG Companies, Inc.
		LIBOR plus 5.5% Secured Debt (Maturity — October 14, 2016)(8)			1,975,000		1,937,558		1,996,754
	Excelitas Technologies Corp.
		LIBOR plus 5.75% Secured Debt (Maturity — December 2, 2016)(8)			3,000,000		2,971,096		3,020,771
	Gentiva Health Services, Inc.
		LIBOR plus 5.0% Secured Debt (Maturity — September 20, 2016)(8)			2,981,250		2,975,289		3,014,789
	Henniges Automotive Holdings, Inc.
		LIBOR plus 10.0% Secured Debt (Maturity — December 7, 2016)(8)			3,000,000		2,941,308		2,941,308
	MLM Holdings, Inc.
		LIBOR plus 5.25% Secured Debt (Maturity — December 1, 2016)(8)			6,982,500		6,879,686		6,897,406
	MultiPlan, Inc.
		LIBOR plus 4.75% Secured Debt (Maturity — August 26, 2017)(8)			3,876,923		3,863,709		3,913,269
	Rite Aid Corporation
		7.5% Bond (Maturity — March 1, 2017)			2,000,000		1,889,335		1,845,874
	SonicWALL, Inc.
		LIBOR plus 6.25% Secured Debt (Maturity — August 1, 2016)(8)			1,794,355		1,797,374		1,807,813
	Terex Corporation
		7.4% Bond (Maturity — January 15, 2014)			2,000,000		2,023,301		2,023,301
	Visant Corporation
		LIBOR plus 5.25% Secured Debt (Maturity — December 28, 2016)(8)			4,987,500		4,891,963		5,057,003
	Vision Solutions, Inc.
		LIBOR plus 6.0% Secured Debt (Maturity — July 23, 2016)(8)			1,925,000		1,612,010		1,631,338

Portfolio Company/Type of Investment(1)(2)				Cost(6)		Fair Value

Marketable Securities and Idle Funds Investments
	Western Refining Inc.
		LIBOR plus 7.5% Secured Debt (Maturity — August 1, 2014)(8)	1,708,883		1,672,628		1,736,654
	Wyle Services Corporation
		LIBOR plus 4.0% Secured Debt (Maturity — September 10, 2016)(8)	3,989,992		3,964,645		4,003,290
	Yankee Cable Acquisition, LLC
		LIBOR plus 4.5% Secured Debt (Maturity — August 26, 2016)(8)	3,990,000		3,933,213		3,990,000
	Other Marketable Securities and Idle Funds Investments(10)		5,529,450		5,653,480		5,707,855

	Subtotal Marketable Securities and Idle Funds Investments				67,970,907		68,752,858

	Total Investments, December 31, 2010			$	390,826,485	$	417,563,932

(1): Debt investments are generally income producing. Equity and warrants are non-income producing, unless otherwise noted.
(2): See Note C for summary geographic location of portfolio companies.
(3): Controlled investments are defined by the Investment Company Act of 1940, as amended ("1940 Act") as investments in which more than 25% of the voting securities are owned or where the ability to nominate greater than 50% of the board representation is maintained.
(4): Affiliate investments are defined by the 1940 Act as investments in which between 5% and 25% of the voting securities are owned.
(5): Non-Control/Non-Affiliate investments are defined by the 1940 Act as investments that are neither Control Investments nor Affiliate Investments.
(6): Principal is net of prepayments. Cost is net of prepayments and accumulated unearned income.
(7): Income producing through dividends or distributions.
(8): Subject to contractual minimum interest rates.
(9): Private placement portfolio investment.
(10): Other Marketable Securities and Idle Funds Investments consists of various registered securities. Other Non-Control/Non-Affiliate investments consist of equity investments in portfolio companies.

Portfolio Company/Type of Investment(1)(2)				Industry	Principal(6)		Cost(6)		Fair Value

Control Investments(3)
	Café Brazil, LLC			Casual Restaurant
		12% Secured Debt (Maturity — April 20, 2011)		Group	$	2,500,000	$	2,487,947	$	2,500,000
		Member Units(7) (Fully diluted 42.3%)						41,837		1,520,000

								2,529,784		4,020,000
	CBT Nuggets, LLC			Produces and Sells
		14% Secured Debt (Maturity — December 31, 2013)		IT Certification		1,680,000		1,656,400		1,680,000
		10% Secured Debt (Maturity — March 31, 2012)		Training Videos		915,000		915,000		915,000
		Member Units(7) (Fully diluted 24.5%)						299,520		1,500,000

								2,870,920		4,095,000
	Ceres Management, LLC (Lambs)			Aftermarket Automotive
		14% Secured Debt (Maturity — May 31, 2013)		Services Chain		2,400,000		2,377,388		2,377,388
		Member Units (Fully diluted 42.0%)						1,200,000		920,000
		Class B Member Units (Non-voting)						218,395		218,395
		9.5% Secured Debt (Lamb's Real Estate Investment I, LLC) (Maturity — August 31, 2014)				537,500		537,500		537,500
		Member Units(7) (Lamb's Real Estate Investment I, LLC) (Fully diluted 50%)						512,500		512,500

								4,845,783		4,565,783
	Condit Exhibits, LLC			Tradeshow Exhibits/
		13% current / 5% PIK Secured Debt (Maturity — July 1,		Custom Displays
			2013)			2,651,514		2,622,107		2,622,107
		Warrants (Fully diluted 28.1%)						300,000		30,000

								2,922,107		2,652,107
	Gulf Manufacturing, LLC			Industrial Metal
		Prime plus 1% Secured Debt (Maturity — August 31,		Fabrication
			2012)			1,200,000		1,193,135		1,200,000
		13% Secured Debt (Maturity — August 31, 2012)				1,000,000		937,602		998,095
		Member Units(7) (Fully diluted 18.4%)						472,000		2,360,000
		Warrants (Fully diluted 8.4%)						160,000		1,080,000

								2,762,737		5,638,095
	Hawthorne Customs & Dispatch Services, LLC			Transportation/
		Member Units(7) (Fully diluted 44.4%)		Logistics				412,500		840,000
		Member Units (Wallisville Real Estate, LLC)(7) (Fully diluted 44.4%)						911,085		911,085

								1,323,585		1,751,085
	Hydratec Holdings, LLC			Agricultural Services
		12.5% Secured Debt (Maturity — October 31, 2012)				2,995,244		2,956,635		2,956,635
		Prime plus 1% Secured Debt (Maturity — October 31, 2012)				350,000		338,667		338,667
		Member Units (Fully diluted 85.1%)						4,100,000		6,620,000

								7,395,302		9,915,302
	Jensen Jewelers of Idaho, LLC			Retail Jewelry
		Prime Plus 2% Secured Debt (Maturity — November 14, 2011)				1,044,000		1,035,321		1,044,000
		13% current / 6% PIK Secured Debt (Maturity — November 14, 2011)				1,067,437		1,055,154		1,067,437
		Member Units(7) (Fully diluted 24.3%)						376,000		290,000

								2,466,475		2,401,437

Portfolio Company/Type of Investment(1)(2)				Industry

Control Investments(3)
	NAPCO Precast, LLC			Precast Concrete
		18% Secured Debt (Maturity — February 1, 2013)		Manufacturing	5,923,077	5,837,759	5,923,077
		Prime Plus 2% Secured Debt (Maturity — February 1, 2013)(8)			3,384,615	3,361,940	3,384,615
		Member Units(7) (Fully diluted 35.3%)				2,020,000	5,220,000

						11,219,699	14,527,692
	OMi Holdings, Inc.			Manufacturer of
		12% Secured Debt (Maturity — April 1, 2013)		Overhead Cranes	6,342,000	6,298,395	6,298,395
		Common Stock (Fully diluted 28.8%)				900,000	270,000

						7,198,395	6,568,395
	Quest Design & Production, LLC			Design and Fabrication
		Prime plus 2% Secured Debt (Maturity — June 30, 2014)		of Custom Display	60,000	60,000	—
		10% Secured Debt (Maturity — June 30, 2014)		Systems	600,000	465,060	200,000
		0% Secured Debt (Maturity — June 30, 2014)			2,060,000	2,060,000	—
		Warrants (Fully diluted 40.0%)				1,595,858	—
		Warrants (Fully diluted 20.0%)				40,000	—

						4,220,918	200,000
	Thermal & Mechanical Equipment, LLC			Heat Exchange / Filtration
		13% current / 5% PIK Secured Debt (Maturity —		Products and Services
			September 25, 2014)		3,345,132	3,301,405	3,301,405
		Prime plus 2% Secured Debt (Maturity — September 25, 2014)(8)			1,050,000	1,043,471	1,043,471
		Warrants (Fully diluted 30.0%)				600,000	600,000

						4,944,876	4,944,876
	Uvalco Supply, LLC			Farm and Ranch Supply
		Member Units (Fully diluted 39.6%)(7)				1,113,243	1,390,000

	Ziegler's NYPD, LLC			Casual Restaurant Group
		Prime plus 2% Secured Debt (Maturity — October 1, 2013)(8)			600,000	595,252	595,252
		13% current / 5% PIK Secured Debt (Maturity — October 1, 2013)			2,808,544	2,775,643	2,775,643
		Warrants (Fully diluted 28.6%)				360,000	360,000

						3,730,895	3,730,895

	Subtotal Control Investments					59,544,719	66,400,667

Portfolio Company/Type of Investment(1)(2)			Industry

Affiliate Investments(4)
	Advantage Millwork Company, Inc.		Manufacturer/Distributor
		12% Secured Debt (Maturity — February 5, 2012)	of Wood Doors	3,066,667	2,970,656	1,200,000
		Warrants (Fully diluted 12.2%)			97,808	—

					3,068,464	1,200,000
	American Sensor Technologies, Inc.		Manufacturer of Commercial/
		Prime plus 0.5% Secured Debt (Maturity — May 31, 2010)(8)	Industrial Sensors	3,800,000	3,800,000	3,800,000
		Warrants (Fully diluted 19.6%)			49,990	820,000

					3,849,990	4,620,000
	California Healthcare Medical Billing, Inc.		Healthcare Billing and Records
		12% Secured Debt (Maturity — October 17, 2013)	Management	1,410,000	1,182,803	1,275,400
		12% Current/6% PIK Secured Debt (Maturity — October 17, 2013)		858,794	842,583	842,583
		Common Stock (Fully diluted 6.0%)			390,000	1,180,000
		Warrants (Fully diluted 12.0%)			240,000	1,280,000

					2,655,386	4,577,983
	Compact Power Equipment Centers, LLC		Light to Medium Duty
		12% Secured Debt (Maturity — September 23, 2014)	Equipment Rental	1,800,000	1,778,702	1,778,702
		Member Units (Fully diluted 6.9%)			688	688

					1,779,390	1,779,390
	Houston Plating & Coatings, LLC		Plating & Industrial
		Prime plus 2% Secured Debt (Maturity — July 19, 2011)	Coating Services	100,000	100,000	100,000
		Prime plus 2% Secured Debt (Maturity — July 18, 2013)		200,000	200,000	200,000
		Member Units(7) (Fully diluted 11.1%)			335,000	3,565,000

					635,000	3,865,000
	Indianapolis Aviation Partners, LLC		FBO/Aviation Support
		12% Secured Debt (Maturity — September 15, 2014)	Services	2,700,000	2,444,759	2,444,759
		Warrants (Fully diluted 9.1%)			450,000	450,000
		Warrants (Fully diluted 9.0%)			227,571	227,571

					3,122,330	3,122,330
	KBK Industries, LLC		Specialty Manufacturer
		14% Secured Debt (Maturity — January 23, 2011)	of Oilfield and	3,937,500	3,853,825	3,853,825
		8% Secured Debt (Maturity — March 1, 2010)	Industrial Products	93,750	93,750	93,750
		8% Secured Debt (Maturity — March 31, 2010)		450,000	450,000	450,000
		Member Units(7) (Fully diluted 14.5%)			187,500	460,000

					4,585,075	4,857,575
	Laurus Healthcare, LP		Healthcare Facilities/Services
		13% Secured Debt (Maturity — May 7, 2012)		2,275,000	2,275,000	2,275,000
		Warrants (Fully diluted 17.5%)			105,000	4,400,000

					2,380,000	6,675,000
	National Trench Safety, LLC		Trench & Traffic
		10% PIK Debt (Maturity — April 16, 2014)	Safety Equipment	447,203	447,203	447,203
		Member Units (Fully diluted 11.7%)			1,792,308	700,000

					2,239,511	1,147,203

Portfolio Company/Type of Investment(1)(2)			Industry

Affiliate Investments(4)
	Olympus Building Services, Inc.		Custodial/Facilities
		12% Secured Debt (Maturity — March 27, 2014)	Services	1,890,000	1,726,931	1,830,000
		12% Current/3% PIK Secured Debt (Maturity — March 27, 2014)		342,782	342,782	342,782
		Warrants (Fully diluted 13.5%)			150,000	480,000

					2,219,713	2,652,782
	Pulse Systems, LLC		Manufacturer of Components
		Warrants (Fully diluted 7.4%)	for Medical Devices		132,856	340,000

	Schneider Sales Management, LLC		Sales Consulting
		13% Secured Debt (Maturity — October 15, 2013)	and Training	1,980,000	1,927,700	1,927,700
		Warrants (Fully diluted 12.0%)			45,000	—

					1,972,700	1,927,700
	Vision Interests, Inc.		Manufacturer/
		13% Secured Debt (Maturity — June 5, 2012)	Installer of Commercial	3,760,000	3,622,160	3,220,000
		Common Stock (Fully diluted 8.9%)	Signage		372,000	—
		Warrants (Fully diluted 11.2%)			160,000	—

					4,154,160	3,220,000
	Walden Smokey Point, Inc.		Specialty Transportation/
		14% current/4% PIK Secured Debt (Maturity — December 30, 2013)	Logistics	4,995,200	4,915,014	4,915,014
		Common Stock (Fully diluted 7.6%)			600,000	1,240,000

					5,515,014	6,155,014
	WorldCall, Inc.		Telecommunication/
		13% Secured Debt (Maturity — April 22, 2011)	Information Services	646,225	646,225	646,225
		Common Stock (Fully diluted 9.9%)			296,631	100,000

					942,856	746,225

		Subtotal Affiliate Investments			39,252,445	46,886,202

MAIN STREET CAPITAL CORPORATION

CONSOLIDATED SCHEDULE OF INVESTMENTS — (Continued)

December 31, 2009

Portfolio Company/Type of Investment(1)(2)				Industry		Cost(6)		Fair Value

Non-Control/Non-Affiliate Investments(5):
	Alon Refining Krots(9)			Petroleum Refiner
		13.5% Secured Debt (Maturity — October 15, 2014)			2,400,000		2,911,128		2,911,128

	Apria Healthcare Group Inc.(9)			Healthcare Services
		11.25% Senior Secured Notes (Maturity — November 1, 2014)			7,200,000		7,335,318		7,956,000

	Audio Messaging Solutions, LLC			Audio Messaging
		12% Secured Debt (Maturity — May 8, 2014)		Services	3,376,800		3,144,392		3,144,392
		Warrants (Fully diluted 5.0%)					215,040		380,000

							3,359,432		3,524,392
	DrillingInfo, Inc.			Information Services for
		12% Secured Debt (Maturity — November 19, 2014)		the Oil and Gas Industry	4,800,000		3,986,221		3,986,221
		Warrants (Fully diluted 3.0%)					750,000		750,000

							4,736,221		4,736,221
	East Teak Fine Hardwoods, Inc.			Hardwood Products
		Common Stock (Fully diluted 3.3%)					178,780		560,000

	Fairway Group Acquisition(9)			Retail Grocery Store
		LIBOR plus 9.5% Secured Debt (Maturity — October 1, 2014)(8)			3,000,000		2,280,805		2,280,805

	Hayden Acquisition, LLC			Manufacturer of Utility
		8% Secured Debt (Maturity — August 9, 2010)		Structures	1,800,000		1,781,303		300,000

	Managed Healthcare(9)			Healthcare Products
	LIBOR plus 3.25% Secured Debt (Maturity — August 31, 2014)				2,000,000		1,463,202		1,670,000

	Support Systems Homes, Inc.			Manages Substance
		15% Secured Debt (Maturity — August 21, 2018)		Abuse Treatment Centers	226,461		226,461		226,461

	Technical Innovations, LLC			Manufacturer of Specialty
		13.5% Secured Debt (Maturity — January 16, 2015)		Cutting Tools and Punches	3,250,000		3,210,176		3,251,280

	Subtotal Non-Control/Non-Affiliate Investments						27,482,826		27,416,287

	Main Street Capital Partners, LLC (Investment Manager)			Asset Management
		100% of Membership Interests					18,000,000		16,036,838

	Total Portfolio Investments, December 31, 2009						144,279,990		156,739,994

	Marketable Securities and Idle Funds Investments			Investments in Secured and
		Western Refining Inc.		Rated Debt Investments,
		LIBOR plus 5% Secured Term Loan (Maturity —		Certificates of Deposit, and	1,773,878		1,727,770		1,727,770
			May 30, 2014)(8)	Diversified Bond Funds
		Pharmanet Development Group, Inc.
		LIBOR plus 7% Secured Term Loan (Maturity — May 29, 2014)(8)			987,500		686,534		686,534
		Other Marketable Securities and Idle Funds Investments			339,000		838,650		838,650

	Total Marketable Securities and Idle Funds Investments, December 31, 2009						3,252,954		3,252,954

Total Investments, December 31, 2009						$	147,532,944	$	159,992,948

Main Street Capital Corporation ("MSCC") was formed on March 9, 2007 for the purpose of (i) acquiring 100% of the equity interests of Main Street Mezzanine Fund, LP ("MSMF") and its general partner, Main Street Mezzanine Management, LLC ("MSMF GP"), (ii) acquiring 100% of the equity interests of Main Street Capital Partners, LLC (the "Investment Manager"), (iii) raising capital in an initial public offering, which was completed in October 2007 (the "IPO"), and (iv) thereafter operating as an internally managed business development company ("BDC") under the Investment Company Act of 1940, as amended (the "1940 Act"). MSMF is licensed as a Small Business Investment Company ("SBIC") by the United States Small Business Administration ("SBA") and the Investment Manager acts as MSMF's manager and investment adviser. Because the Investment Manager, which employs all of the executive officers and other employees of MSCC, is wholly owned by MSCC, MSCC does not pay any external investment advisory fees but instead incurs the net operating costs associated with employing investment and portfolio management professionals through the Investment Manager. The IPO and related transactions discussed above were consummated in October 2007 and are collectively termed the "Formation Transactions."

On January 7, 2010, MSCC consummated transactions (the "Exchange Offer") to exchange 1,239,695 shares of its common stock for approximately 88% of the total dollar value of the limited partner interests in Main Street Capital II, LP ("MSC II" and, together with MSMF, the "Funds"). Pursuant to the terms of the Exchange Offer, 100% of the membership interests in the general partner of MSC II, Main Street Capital II GP, LLC ("MSC II GP"), were also transferred to MSCC for no consideration. MSC II commenced operations in January 2006, is an investment fund that operates as an SBIC and is also managed by the Investment Manager. The Exchange Offer and related transactions, including the transfer of the MSC II GP interests, are collectively termed the "Exchange Offer Transactions" (see Note J).

Unless otherwise noted or the context otherwise indicates, the terms "we," "us," "our" and "Main Street" refer to MSCC and its subsidiaries, including MSMF, MSC II, and the Taxable Subsidiaries.

Main Street's financial statements are prepared in accordance with U.S. generally accepted accounting principles ("U.S. GAAP"). For the year ended December 31, 2010, Main Street's consolidated financial statements include the accounts of MSCC and its consolidated subsidiaries, including the Funds. For the year ended 2009, Main Street's consolidated financial statements include the accounts of MSCC and its consolidated subsidiaries, including MSMF. Portfolio investments, as used herein, refers to all of Main Street's portfolio investments in lower middle market ("LMM") companies, private placement portfolio investments, and the investment in the Investment Manager and excludes all "Marketable securities and idle funds investments." Private placement portfolio investments include investments made through direct or secondary purchases of interest-bearing securities in companies that are generally larger in size than the LMM companies included as part of Main Street's portfolio investments. The Investment Manager is accounted for as a portfolio investment (see Note D). "Marketable securities and idle funds investments" are classified as financial instruments and are reported separately on Main Street's Consolidated Balance Sheets and Consolidated Schedule of Investments due to the nature of such investments (see Note B.13). Main Street's

results of operations and cash flows for the years ended December 31, 2010, 2009, and 2008, and financial position as of December 31, 2010 and 2009, are presented on a consolidated basis. The effects of all intercompany transactions between Main Street and its consolidated subsidiaries have been eliminated in consolidation. Certain reclassifications have been made to prior period balances to conform with the current financial statement presentation, including the reclassification of private placement portfolio investments which were formerly classified as "Marketable securities and idle funds investments" and are now classified as portfolio investments in the "Non-Control/Non-Affiliate investments" category due to Main Street's current intent to hold such investments until their maturity and the fact that their terms adhere more to Main Street's portfolio investment strategy.

Under the investment company rules and regulations pursuant to Article 6 of Regulation S-X and the Audit and Accounting Guide for Investment Companies issued by the American Institute of Certified Public Accountants (the "AICPA Guide"), Main Street is precluded from consolidating portfolio company investments, including those in which it has a controlling interest, unless the portfolio company is another investment company. An exception to this general principle in the AICPA Guide occurs if Main Street owns a controlled operating company that provides all or substantially all of its services directly to Main Street or to an investment company of Main Street. None of the investments made by Main Street qualify for this exception. Therefore, Main Street's portfolio investments are carried on the balance sheet at fair value, as discussed further in Note B, with any adjustments to fair value recognized as "Net Change in Unrealized Appreciation (Depreciation)" on the Statement of Operations until the investment is exited, resulting in any gain or loss on exit being recognized as a "Net Realized Gain (Loss) from Investments."

Main Street classifies its portfolio investments in accordance with the requirements of the 1940 Act. Under the 1940 Act, "Control Investments" are defined as investments in which Main Street owns more than 25% of the voting securities or has rights to maintain greater than 50% of the board representation. Under the 1940 Act, "Affiliate Investments" are defined as investments in which Main Street owns between 5% and 25% of the voting securities. Under the 1940 Act, "Non-Control/Non-Affiliate Investments" are defined as investments that are neither Control investments nor Affiliate investments. The "Investment in affiliated Investment Manager" represents Main Street's investment in a wholly owned investment manager subsidiary that is accounted for as a portfolio investment.

Main Street accounts for its LMM portfolio investments, private placement portfolio investments, and the investment in the Investment Manager at fair value. As a result, Main Street adopted the provisions of the Financial Accounting Standards Board ("FASB") Accounting Standards Codification ("Codification" or "ASC") 820, Fair Value Measurements and Disclosures, in the first quarter of 2008. ASC 820 defines fair value, establishes a framework for measuring fair value, establishes a fair value hierarchy based on the quality of inputs used to measure fair value and enhances disclosure requirements for fair value measurements. ASC 820 requires Main Street to assume that the portfolio investment is to be sold in the principal market to independent market participants, or in the absence of a principal market, in the most advantageous market, which may be a hypothetical market. Market participants are defined as buyers and sellers in the principal or most advantageous market that are independent, knowledgeable, and willing and able to transact. With the adoption of this statement, Main Street incorporated the income approach to estimate the fair value of its LMM portfolio debt investments principally using a yield-to-maturity model.

Main Street's portfolio strategy calls for it to invest primarily in illiquid securities issued by private, LMM companies as well as privately placed debt securities issued by private, middle market companies that are generally larger in size than the LMM companies. These portfolio investments may be subject to restrictions on resale and will generally have no established trading market. Main Street determines in good faith the fair value of its portfolio investments pursuant to a valuation policy in accordance with ASC 820 and a valuation process approved by its Board of Directors and in accordance with the 1940 Act. Main Street reviews external events, including private mergers, sales and acquisitions involving comparable companies, and includes these events in the valuation process. Main Street's valuation policy and process are intended to provide a consistent basis for determining the fair value of the portfolio.

For valuation purposes, control investments are composed of equity and debt securities for which Main Street has a controlling interest in the portfolio company or has the ability to nominate a majority of the portfolio company's board of directors. Market quotations are generally not readily available for Main Street's control investments. As a result, Main Street determines the fair value of control investments using a combination of market and income approaches. Under the market approach, Main Street will typically use the enterprise value methodology to determine the fair value of these investments. The enterprise value is the fair value at which an enterprise could be sold in a transaction between two willing parties, other than through a forced or liquidation sale. Typically, private companies are bought and sold based on multiples of earnings before interest, taxes, depreciation and amortization ("EBITDA"), cash flows, net income, revenues, or in limited cases, book value. There is no single methodology for estimating enterprise value. For any one portfolio company, enterprise value is generally described as a range of values from which a single estimate of enterprise value is derived. In estimating the enterprise value of a portfolio company, Main Street analyzes various factors, including the portfolio company's historical and projected financial results. Main Street allocates the enterprise value to investments in order of the legal priority of the investments. Main Street will also use the income approach to determine the fair value of these securities, based on projections of the discounted future free cash flows that the portfolio company or the debt security will likely generate. The valuation approaches for Main Street's control investments estimate the value of the investment if it were to sell, or exit, the investment, assuming the highest and best use of the investment by market participants. In addition, these valuation approaches consider the value associated with Main Street's ability to control the capital structure of the portfolio company, as well as the timing of a potential exit.

For valuation purposes, non-control LMM portfolio investments are composed of debt and equity securities for which Main Street does not have a controlling interest in the portfolio company, or the ability to nominate a majority of the portfolio company's board of directors. Market quotations for non-control LMM investments are generally not readily available. For non-control LMM portfolio investments, Main Street uses a combination of the market and income approaches to value its equity investments and the income approach to value its debt instruments. For non-control LMM debt investments, Main Street determines the fair value primarily using a yield approach that analyzes the discounted cash flows of interest and principal for the debt security, as set forth in the associated loan agreements, as well as the financial position and credit risk of each of these portfolio investments. Main Street's estimate of the expected repayment date of a LMM debt security is generally the legal maturity date of the instrument, as Main Street generally intends to hold its loans to maturity. The yield analysis considers changes in leverage levels, credit quality, portfolio company performance and other factors. Main Street will use the value determined by the yield analysis as the fair value for that security; however, because of Main Street's general intent to hold its loans to maturity, the fair value will not exceed the face amount of the LMM debt security. A change in the assumptions that Main Street uses to estimate the fair value of its LMM debt securities using the yield analysis could have a material impact on the determination of fair value. If there is deterioration in credit quality or a debt security is in workout status, Main Street may consider other factors in determining the fair value of a LMM debt security,

including the value attributable to the debt security from the enterprise value of the portfolio company or the proceeds that would be received in a liquidation analysis.

Pursuant to its internal valuation process, Main Street performs valuation procedures on each LMM portfolio company once a quarter. In addition to its internal valuation process, in arriving at estimates of fair value for portfolio companies, Main Street, among other things, consults with a nationally recognized independent advisor. The nationally recognized independent advisor is generally consulted relative to each LMM portfolio investment at least once in every calendar year, and for new LMM portfolio companies, at least once in the twelve-month period subsequent to the initial investment. In certain instances, Main Street may determine that it is not cost-effective, and as a result is not in its stockholders' best interest, to consult with the nationally recognized independent advisor on one or more LMM portfolio companies. Such instances include, but are not limited to, situations where the fair value of Main Street's investment in a LMM portfolio company is determined to be insignificant relative to the total investment portfolio. Main Street consulted with its independent advisor in arriving at Main Street's determination of fair value on a total of 34 portfolio companies, including 33 LMM portfolio companies and our affiliated Investment Manager, for the year ended December 31, 2010, representing approximately 79% of the total LMM portfolio and affiliated Investment Manager investments at fair value as of December 31, 2010. Main Street consulted with its independent advisor relative to Main Street's determination of fair value on 8, 10, 8, and 8 LMM portfolio investments for the quarters ended March 31, June 30, September 30, and December 31, 2010, respectively. The Board of Directors of Main Street has the final responsibility for reviewing and approving, in good faith, Main Street's estimate of the fair value for the investments consistent with the 1940 Act requirements.

Main Street's private placement portfolio investments primarily consist of direct or secondary purchases of interest-bearing securities in companies that are generally larger in size than the LMM companies included in Main Street's portfolio. For valuation purposes, all of Main Street's private placement portfolio investments are non-control investments and are composed of debt securities for which Main Street does not have a controlling interest in the portfolio company, or the ability to nominate a majority of the portfolio company's board of directors. Main Street primarily uses observable inputs to determine the fair value of these investments through obtaining third party quotes or other independent pricing. As of December 31, 2010, Main Street had privately placed portfolio investments in 16 companies collectively totaling approximately $67.1 million in fair value with a total cost basis of approximately $65.6 million. The weighted average revenues for the 16 privately placed portfolio company investments was approximately $352 million. All of Main Street's privately placed portfolio investments were in the form of debt investments and 71% of such debt investments at cost were secured by first priority liens on portfolio company assets. The weighted average effective yield on Main Street's privately placed portfolio debt investments was approximately 12.5% as of December 31, 2010.

Due to the inherent uncertainty in the valuation process, Main Street's estimate of fair value may differ materially from the values that would have been used had a ready market for the securities existed. In addition, changes in the market environment, portfolio company performance and other events that may occur over the lives of the investments may cause the gains or losses ultimately realized on these investments to be materially different than the valuations currently assigned. Main Street estimates the fair value of each individual investment and records changes in fair value as unrealized appreciation or depreciation.

Main Street uses a standard internal portfolio investment rating system in connection with its investment oversight, portfolio management/analysis and investment valuation procedures. This system takes into account both quantitative and qualitative factors of the portfolio company and the investments held therein.

Main Street believes its investments as of December 31, 2010 and 2009 approximate fair value as of those dates based on the market in which Main Street operates and other conditions in existence at those reporting periods.

The preparation of financial statements in conformity with accounting principles generally accepted in the United States of America requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenue and expenses during the period. Actual results may differ from these estimates under different conditions or assumptions. Additionally, as explained above, the financial statements include portfolio investments whose values have been estimated by Main Street with the oversight, review and approval by Main Street's Board of Directors in the absence of readily ascertainable market values. Because of the inherent uncertainty of the portfolio investment valuations, those estimated values may differ significantly from the values that would have been used had a readily available market for the investments existed, and it is reasonably possible that the differences could be material.

Cash and cash equivalents consist of highly liquid investments with an original maturity of three months or less at the date of purchase. Cash and cash equivalents are carried at cost, which approximates fair value.

Marketable securities and idle funds investments include investments in certificates of deposit, U.S. government agency securities, intermediate-term secured debt, independently rated debt investments, and diversified bond funds. See the "Consolidated Schedule of Investments" for more information on marketable securities and idle funds investments.

Interest and dividend income is recorded on the accrual basis to the extent amounts are expected to be collected. Dividend income is recorded as dividends are declared or at the point an obligation exists for the portfolio company to make a distribution. In accordance with Main Street's valuation policy, accrued interest and dividend income is evaluated periodically for collectability. When a loan or debt security becomes 90 days or more past due, and if Main Street otherwise does not expect the debtor to be able to service all of its debt or other obligations, Main Street will generally place the loan or debt security on non-accrual status and cease recognizing interest income on that loan or debt security until the borrower has demonstrated the ability and intent to pay contractual amounts due. If a loan or debt security's status significantly improves regarding ability to service the debt or other obligations, or if a loan or debt security is fully impaired, sold or written off, it will be removed from non-accrual status.

While not significant to its total portfolio, Main Street holds debt and preferred equity instruments in its investment portfolio that contain payment-in-kind ("PIK") interest and cumulative dividend provisions. The PIK interest, computed at the contractual rate specified in each debt agreement, is added to the principal balance of the debt and is recorded as interest income. Thus, the actual collection of this interest may be deferred until the time of debt principal repayment. Cumulative dividends are recorded as dividend income, and any dividends in arrears are added to the balance of the preferred equity investment. The actual collection of dividends in arrears may be deferred until such time as the preferred equity is redeemed. To maintain regulated investment company ("RIC") tax treatment (as discussed below), these non-cash sources of income will need to be paid out to stockholders in the form of distributions, even though Main Street may not have collected the PIK interest and cumulative dividends in cash.

As of December 31, 2010, Main Street had two investments on non-accrual status, which comprised approximately 2.6% of the investment portfolio at fair value. At December 31, 2009, Main Street had three

investments on non-accrual status, which comprised approximately 1.1% of the investment portfolio at fair value.

Deferred financing costs include SBIC debenture commitment fees and SBIC debenture leverage fees which have been capitalized and which are amortized into interest expense over the term of the debenture agreement (10 years).

Deferred financing costs also include costs related to a two-year term treasury line of credit and a three-year term investment credit facility. These costs have been capitalized and are amortized into interest expense over their respective terms. The treasury line of credit was voluntarily terminated in 2009, and the remaining unamortized costs associated with the treasury line of credit were expensed in 2009.

Main Street may periodically provide services, including structuring and advisory services, to its portfolio companies. For services that are separately identifiable and evidence exists to substantiate fair value, income is recognized as earned, which is generally when the investment or other applicable transaction closes. Fees received in connection with debt financing transactions for services that do not meet these criteria are treated as debt origination fees and are accreted into interest income over the life of the financing.

Main Street capitalizes upfront debt origination fees received in connection with financings and reflects such fees as unearned income netted against investments. Main Street will also capitalize and offset direct loan origination costs against the origination fees received. The unearned income from the fees, net of direct debt origination costs, is accreted into interest income based on the effective interest method over the life of the financing.

In connection with its portfolio debt investments, Main Street sometimes receives nominal cost warrants ("nominal cost equity") that are valued as part of the negotiation process with the particular portfolio company. When Main Street receives nominal cost equity, Main Street allocates its cost basis in its investment between its debt securities and its nominal cost equity at the time of origination. Any resulting discount from recording the debt is reflected as unearned income, which is netted against the debt investment, and accreted into interest income based on the effective interest method over the life of the debt.

Main Street accounts for its share-based compensation plans using the fair value method, as prescribed by ASC 718, Compensation — Stock Compensation. Accordingly, for restricted stock awards, Main Street measures the grant date fair value based upon the market price of its common stock on the date of the grant and amortizes that fair value to share-based compensation expense over the requisite service period or vesting term.

MSCC may choose to carry forward taxable income in excess of current year distributions into the next tax year and pay a 4% excise tax on such income. Any such carryover taxable income must be distributed through a dividend declared prior to filing the final tax return related to the year which generated such taxable income.

11. Net Realized Gains or Losses from Investments and Net Change in Unrealized Appreciation or Depreciation from Investments

Realized gains or losses are measured by the difference between the net proceeds from the sale or redemption of an investment and the cost basis of the investment, without regard to unrealized appreciation or depreciation previously recognized, and includes investments written-off during the period net of recoveries and realized gains or losses from in-kind redemptions. Net change in unrealized appreciation or depreciation from investments reflects the net change in the valuation of the investment portfolio and financial instruments pursuant to Main Street's valuation guidelines and the reclassification of any prior period unrealized appreciation or depreciation on exited investments.

Main Street places its cash in financial institutions, and, at times, such balances may be in excess of the federally insured limit.

Fair value estimates are made at discrete points in time based on relevant information. These estimates may be subjective in nature and involve uncertainties and matters of significant judgment and, therefore, cannot be determined with precision. Main Street believes that the carrying amounts of its financial instruments, consisting of cash and cash equivalents, marketable securities, receivables, accounts payable and accrued liabilities approximate the fair values of such items. Marketable securities and idle funds investments generally include investments in certificates of deposit, U.S. government agency securities, intermediate-term secured debt, independently rated debt investments, and diversified bond funds. The fair value determination for these investments under the provisions of ASC 820 primarily consists of Level 2 observable inputs.

The SBIC debentures remain a strategic advantage due to their flexible structure, long-term duration, and low fixed interest rates. As part of the Exchange Offer Transactions, Main Street elected the fair value option under ASC 825, Financial Instruments ("ASC 825") relating to accounting for debt obligations at their fair value, for those SBIC debentures acquired (the "Acquired Debentures"). The fair value option was elected for the Acquired Debentures as part of the acquisition accounting related to the Exchange Offer. In order to provide for a more consistent basis of presentation, Main Street has elected and will continue to elect the fair value option for SBIC debentures issued by MSC II subsequent to the Exchange Offer. Once the fair value option is elected for a given SBIC debenture, the deferred loan costs associated with the debenture are fully expensed in the current period to "Net Change in Unrealized Appreciation (Depreciation) — SBIC debentures" as part of the fair value adjustment. Interest associated with SBIC debentures valued at fair value is expensed to "Interest" expense.

Basic and diluted per share calculations are computed utilizing the weighted average number of shares of common stock outstanding for the period. Main Street adopted the amended guidance in ASC 260, Earnings Per Share. Based on the guidance, Main Street determined that unvested shares of restricted stock are participating securities and should therefore be included in the basic earnings per share calculation. As a result, for all periods presented, there is no difference between diluted earnings per share and basic earnings per share amounts.

As a result of the Exchange Offer Transactions, the net earnings attributable to the remaining externally owned noncontrolling interest in MSC II is excluded from all per share amounts presented and the per share amounts only reflect the net earnings attributable to Main Street's ownership interest in MSC II.

In June 2009, FASB issued ASC 810, Amendments to FASB Interpretation No. 46(R) ("ASC 810"), which amends the guidance in FASB Interpretation No. ("FIN") 46(R), Consolidation of Variable Interest Entities. It requires reporting entities to evaluate former qualifying special-purpose entities ("QSPEs") for consolidation, changes the approach to determining the primary beneficiary of a variable interest entity (a "VIE") from a quantitative assessment to a qualitative assessment designed to identify a controlling financial interest, and increases the frequency of required reassessments to determine whether a company is the primary beneficiary of a VIE. It also clarifies, but does not significantly change, the characteristics that identify a VIE. ASC 810 requires additional year-end and interim disclosures for public and non-public companies. ASC 810 is effective as of the beginning of a company's first fiscal year that begins after November 15, 2009 and for subsequent interim and annual reporting periods. Main Street adopted ASC 810 on January 1, 2010. The FASB agreed at its January 27, 2010 meeting to issue an Accounting Standards Update ("ASU") to finalize its proposal to indefinitely defer ASC 810 for reporting enterprises' interests in entities that either have all of the characteristics of investment companies or for which it is industry practice to apply measurement principles for financial reporting purposes consistent with those that apply to investment companies. The provisions of ASC 810 will not have any impact on Main Street's financial condition or results of operations.

In December 2007, the FASB issued ASC 805, Business Combinations. Under ASC 805, an acquiring entity will be required to recognize all the assets acquired and liabilities assumed in a transaction at the acquisition-date fair value, with limited exceptions, replacing the previous cost-allocation process. ASC 805 also includes a substantial number of new disclosure requirements. ASC 805 is to be applied prospectively to business combinations for which the acquisition date is on or after the beginning of the first annual reporting period beginning on or after December 15, 2008. Early adoption is prohibited. Main Street adopted ASC 805 on January 1, 2009. Main Street accounted for the Exchange Offer under ASC 805 with the impact on the financial statements discussed in Note J.

In connection with valuing investments, Main Street adopted the provisions of ASC 820 in the first quarter of 2008. ASC 820 defines fair value, establishes a framework for measuring fair value, establishes a fair value hierarchy based on the quality of inputs used to measure fair value, and enhances disclosure requirements for fair value measurements. Main Street accounts for its investments at fair value.

In accordance with ASC 820, Main Street has categorized its investments based on the priority of the inputs to the valuation technique, into a three-level fair value hierarchy. The fair value hierarchy gives the highest priority to quoted prices in active markets for identical investments (Level 1) and the lowest priority to unobservable inputs (Level 3).

Investments recorded on Main Street's balance sheet are categorized based on the inputs to the valuation techniques as follows:

As required by ASC 820, when the inputs used to measure fair value fall within different levels of the hierarchy, the level within which the fair value measurement is categorized is based on the lowest level input that is significant to the fair value measurement in its entirety. For example, a Level 3 fair value measurement may include inputs that are observable (Levels 1 and 2) and unobservable (Level 3). Therefore, gains and losses for such investments categorized within the Level 3 table below may include changes in fair value that are attributable to both observable inputs (Levels 1 and 2) and unobservable inputs (Level 3). Main Street conducts reviews of fair value hierarchy classifications on a quarterly basis. Changes in the observability of valuation inputs may result in a reclassification for certain investments.

As of December 31, 2010 and 2009, all of Main Street's private placement portfolio investments, marketable securities and idle funds investments consisted primarily of investments in debt investments, independently rated debt investments, certificates of deposit, and diversified bond funds. The fair value determination for these investments primarily consisted of observable inputs in non-active markets. As a result, all of Main Street's private placement portfolio investments, marketable securities and idle funds investments were categorized as Level 2 as of December 31, 2010 and 2009.

As of December 31, 2010 and 2009, all of Main Street's LMM portfolio investments consisted of illiquid securities issued by private companies. The fair value determination for these investments primarily consisted of unobservable inputs. As a result, all of Main Street's LMM portfolio investments were categorized as Level 3. The fair value determination of each portfolio investment required one or more of the following unobservable inputs:

The following table provides a summary of changes in fair value of Main Street's Level 3 portfolio investments for the year ended December 31, 2010:

The following table provides a summary of changes in fair value of the Level 3 SBIC Debentures recorded at fair value for the year ended December 31, 2010:

At December 31, 2010 and 2009, Main Street's investments and SBIC Debentures at fair value were categorized as follows in the fair value hierarchy for ASC 820 purposes:

For the year ended December 31, 2010, there were no transfers within the three fair value hierarchy levels.

Main Street's LMM portfolio investments principally consist of secured debt, equity warrants and direct equity investments in privately held, LMM companies. The LMM debt investments are secured by either a first or second lien on the assets of the portfolio company, generally bear interest at fixed rates, and generally mature between five and seven years from the original investment. In most LMM portfolio companies, Main Street also receives nominally priced equity warrants and/or makes direct equity investments, usually in connection with a debt investment.

Investment income, consisting of interest, dividends and fees, can fluctuate dramatically due to various factors, including repayment of a debt investment or sale of an equity interest. Revenue recognition in any given year could be highly concentrated among several portfolio companies. For the years ended December 31, 2010 and 2009, Main Street did not record investment income from any portfolio company in excess of 10% of total investment income.

As of December 31, 2010, Main Street had debt and equity investments in 44 LMM portfolio companies with an aggregate fair value of $279.6 million and a weighted average effective yield on its LMM debt investments of approximately 14.5%. Approximately 77% of Main Street's total LMM portfolio investments at cost were in the form of debt investments and 91% of such debt investments at cost were secured by first priority liens on the assets of Main Street's LMM portfolio companies as of December 31, 2010. At December 31, 2010, Main Street had equity ownership in approximately 91% of its LMM portfolio companies and the average fully diluted equity ownership in those portfolio companies was approximately 33%. As of December 31, 2009, Main Street had debt and equity investments in 35 LMM portfolio companies with an aggregate fair value of $125.9 million and a weighted average effective yield on its LMM debt investments of approximately 14.3%. The weighted average yields were computed using the effective interest rates for all debt investments at December 31, 2010 and 2009, including amortization of deferred debt origination fees and accretion of original issue discount but excluding liquidation fees payable upon repayment and any debt investments on non-accrual status.

Summaries of the composition of Main Street's LMM investment portfolio at cost and fair value as a percentage of total LMM portfolio investments are shown in the following table:

Cost:

Professional services	15.4	%	12.7	%
Equipment rental	8.4	%	3.6	%
Information services	7.8	%	5.1	%
Retail	7.4	%	7.5	%
Industrial equipment	7.2	%	6.4	%
Industrial services	7.2	%	5.0	%
Media/Marketing	6.6	%	0.0	%
Metal fabrication	6.3	%	2.5	%
Electronics manufacturing	5.2	%	7.1	%
Health care services	5.0	%	4.7	%
Precast concrete manufacturing	4.4	%	9.7	%
Restaurant	3.3	%	5.6	%
Custom wood products	3.0	%	6.7	%
Agricultural services	2.8	%	6.6	%
Consumer Products	2.6	%	0.0	%
Manufacturing	2.4	%	4.1	%
Governmental services	1.8	%	2.0	%
Transportation/Logistics	1.3	%	6.1	%
Health care products	1.2	%	3.0	%
Infrastructure products	0.7	%	1.6	%

	100.0	%	100.0	%

Fair Value:

Professional services	14.3	%	12.2	%
Information services	8.5	%	4.4	%
Industrial services	7.8	%	7.0	%
Equipment rental	7.3	%	2.3	%
Health care services	7.1	%	9.1	%
Retail	6.6	%	6.6	%
Metal fabrication	6.5	%	4.5	%
Industrial equipment	6.3	%	5.2	%
Media/Marketing	5.9	%	0.0	%
Electronics manufacturing	5.0	%	6.2	%
Precast concrete manufacturing	4.9	%	11.5	%
Restaurant	3.7	%	6.2	%
Agricultural services	3.3	%	7.9	%
Custom wood products	3.0	%	1.6	%
Manufacturing	2.7	%	3.9	%
Consumer Products	2.3	%	0.0	%
Transportation/Logistics	1.8	%	6.3	%
Governmental services	1.8	%	2.1	%
Health care products	1.1	%	2.9	%
Infrastructure products	0.1	%	0.1	%

	100.0	%	100.0	%

At December 31, 2010, Main Street had no investments that were greater than 10% of its total investment portfolio at fair value. At December 31, 2009, Main Street had one investment that was greater than 10% of its total investment portfolio at fair value. That investment represented approximately 12% of the portfolio at fair value.

As part of the Formation Transactions, the Investment Manager became a wholly owned subsidiary of MSCC. However, the Investment Manager is accounted for as a portfolio investment, since the Investment Manager is not an investment company and since it conducts a significant portion of its investment management activities for parties outside of MSCC and its consolidated subsidiaries. The Investment Manager receives recurring investment management fees from MSC II pursuant to a separate investment advisory agreement. The payments due under the investment advisory agreement were fixed at $3.3 million per year, paid quarterly, until September 30, 2010. Subsequent to September 30, 2010, under the investment advisory agreement, MSC II is obligated to pay a 2% annualized management fee based upon MSC II assets under management. Subsequent to the closing of the Exchange Offer, the investment in the Investment Manager was reduced to reflect the pro rata portion of the MSC II management fees acquired by MSCC. The Investment Manager also receives certain management, consulting and advisory fees for providing these services for third parties, and collectively with the MSC II management fees attributable to the remaining noncontrolling interest in MSC II, the "External Services." The portfolio investment in the Investment Manager is accounted for using fair value accounting, with the fair value determined by Main Street and approved, in good faith, by Main Street's Board of Directors, based on the same valuation methodologies applied to determine the original valuation. The valuation for the Investment Manager is based on the total estimated present value of the net cash flows received for the External Services, over the estimated dollar averaged life of the related investment management, advisory or consulting contract, and is also based on comparable public market

transactions. The net cash flows utilized in the valuation of the Investment Manager exclude any revenues and expenses from MSCC and its subsidiaries, but include the revenues attributable to External Services, and are reduced by an estimated allocation of costs related to providing such External Services. Any change in fair value of the investment in the Investment Manager is recognized on Main Street's statement of operations as "Unrealized appreciation (depreciation) in Investment in affiliated Investment Manager," with a corresponding increase (in the case of appreciation) or decrease (in the case of depreciation) to "Investment in affiliated Investment Manager" on Main Street's balance sheet. As part of the Exchange Offer Transactions, the investment in the Investment Manager was reduced $13.7 million and recorded against "Additional paid-in capital" as an adjustment to the original valuation recorded as part of the Formation Transactions. Main Street believes that the valuation for the Investment Manager will generally decrease over the life of the investment management, advisory and consulting contracts attributable to third parties, absent obtaining additional recurring cash flows from performing External Services for other external investment entities or other third parties.

The Investment Manager has elected, for tax purposes, to be treated as a taxable entity and is taxed at normal corporate tax rates based on its taxable income. The taxable income of the Investment Manager may differ from its book income due to temporary book and tax timing differences, as well as permanent differences. The Investment Manager provides for any current taxes payable and deferred tax items in its separate financial statements.

MSCC has a support services agreement with the Investment Manager that is structured to provide reimbursement to the Investment Manager for any personnel, administrative and other costs it incurs in conducting its operational and investment management activities in excess of the fees received for providing management advisory services. As a wholly owned subsidiary of MSCC, the Investment Manager manages the day-to-day operational and investment activities of MSCC and its subsidiaries. The Investment Manager pays personnel and other administrative expenses, except those specifically required to be borne by MSCC which principally include direct costs that are specific to MSCC's status as a publicly traded entity. The expenses paid by the Investment Manager include the cost of salaries and related benefits, rent, equipment and other administrative costs required for day-to-day operations.

Pursuant to the support services agreement with MSCC, the Investment Manager is reimbursed by MSCC for its excess cash expenses associated with providing investment management and other services to MSCC and its subsidiaries, as well as third parties. Each quarter, as part of the support services agreement, MSCC makes payments to cover all cash expenses incurred by the Investment Manager, less fees that the Investment Manager receives pursuant to long-term investment advisory agreements and consulting agreements. Subsequent to the consolidation of MSC II in connection with the Exchange Offer, the management fees paid by MSC II to the Investment Manager are now included in "Expenses reimbursed to affiliated Investment Manager" on the Statement of Operations along with any additional net costs reimbursed by MSCC to the Investment Manager pursuant to the support services agreement. For the year ended December 31, 2010, the expenses reimbursed by MSCC and management fees paid by MSC II to the Investment Manager totaled $5.3 million. For the year ended December 31, 2009, the expenses reimbursed by MSCC to the Investment Manager were $0.6 million.

In its separate stand-alone financial statements as summarized below, the Investment Manager recognized an $18 million intangible asset related to the investment advisory agreement with MSC II consistent with Staff Accounting Bulletin No. 54, Application of "Pushdown" Basis of Accounting in Financial Statements of Subsidiaries Acquired by Purchase ("SAB 54"). Under SAB 54, push-down accounting is required in "purchase transactions that result in an entity becoming substantially wholly owned." In this case, MSCC acquired 100% of the equity interests in the Investment Manager. Because the $18 million value attributed to MSCC's investment in the Investment Manager was derived from the long-term, recurring management fees

under the investment advisory agreement with MSC II, the same methodology used to determine the $18 million valuation of the Investment Manager was utilized to establish the push-down accounting basis for the intangible asset. The intangible asset is being amortized over the estimated economic life of the investment advisory agreement with MSC II. For the years ended December 31, 2010, 2009, and 2008, the Investment Manager recognized $1.1 million, $1.0 million, and $1.2 million in amortization expense associated with the intangible asset. Amortization expense is not included in the expenses reimbursed by MSCC to the Investment Manager based upon the support services agreement since it is non-cash in nature.

Summarized financial information from the separate financial statements of the Investment Manager is as follows:

		Years Ended December 31,

		2010			2009			2008
		(Unaudited)
Management fee income from Main Street Capital II		$	3,054,011		$	3,325,200		$	3,325,200
Other management advisory fees			369,595			287,200			47,750

	Total income		3,423,606			3,612,400			3,372,950
Salaries, benefits and other personnel costs			(4,542,861	)		(3,415,837	)		(3,483,336	)
Occupancy expense			(308,380	)		(348,761	)		(184,285	)
Professional expenses			(102,122	)		(12,794	)		(81,208	)
Amortization expense — intangible asset			(1,084,943	)		(950,589	)		(1,174,207	)
Other expenses			(679,365	)		(404,876	)		(630,956	)
Expense reimbursement from MSCC			2,209,122			569,868			1,006,835

	Total net expenses		(4,508,549	)		(4,562,989	)		(4,547,157	)

Net income		$	(1,084,943	)	$	(950,589	)	$	(1,174,207	)

Deferred financing costs balances as of December 31, 2010 and 2009 are as follows:

Estimated aggregate amortization expense for each of the five years succeeding December 31, 2010 and thereafter is as follows:

SBIC debentures payable at December 31, 2010 and 2009 were $180 million and $65 million, respectively. SBIC debentures provide for interest to be paid semi-annually, with principal due at the applicable 10-year maturity date. The weighted average interest rate as of December 31, 2010 and 2009 was 5.2% and 5.0%, respectively. The first principal maturity due under the existing SBIC debentures is in 2013, and the weighted average duration is approximately 7.1 years. For the year ended December 31, 2010, Main Street recognized $8.5 million in interest expense attributable to the SBIC debentures. In accordance with SBA regulations, the Funds are precluded from incurring additional non-SBIC debt without the prior approval of the SBA. The Funds are subject to annual compliance examinations by the SBA. There have been no historical findings resulting from these examinations.

As of December 31, 2010, the recorded value of the SBIC debentures was $155.6 million which consisted of (i) $70.6 million recorded at fair value, or $24.4 million less than the $95.0 million face value of these SBIC debentures, and (ii) $85.0 million reported at face value and held in MSMF, the SBIC that was owned by Main Street prior to the Exchange Offer. As of December 31, 2010, had Main Street adopted the fair value option under ASC 825 for all of its SBIC debentures, Main Street estimates the fair value of its SBIC debentures would be approximately $142.8 million, or $37.2 million less than the face value of the SBIC debentures.

Pooling Date				Amount

9/24/2003	9/1/2013	5.7620	%	$	4,000,000
3/24/2004	3/1/2014	5.0070	%		3,000,000
9/22/2004	9/1/2014	5.5710	%		9,000,000
9/22/2004	9/1/2014	5.5390	%		6,000,000
3/23/2005	3/1/2015	5.9250	%		2,000,000
3/23/2005	3/1/2015	5.8930	%		2,000,000
9/28/2005	9/1/2015	5.7960	%		19,100,000
3/28/2007	3/1/2017	6.2310	%		3,900,000
3/28/2007	3/1/2017	6.2630	%		1,000,000
3/28/2007	3/1/2017	6.3170	%		5,000,000
3/24/2010	3/1/2020	4.5140	%		10,000,000

Balances as of December 31, 2009					65,000,000
Debentures Acquired in the Exchange Offer on January 7, 2010
9/27/2006	9/1/2016	6.4760	%		5,000,000
3/28/2007	3/1/2017	6.3170	%		7,100,000
9/26/2007	9/1/2017	6.4340	%		19,800,000
9/26/2007	9/1/2017	6.4690	%		7,900,000
3/26/2008	3/1/2018	6.3770	%		10,200,000
9/23/2009	9/1/2019	4.9500	%		20,000,000

Balances as of Consummation of the Exchange Offer					135,000,000
9/22/2010	9/1/2020	3.9320	%		10,000,000
9/22/2010	9/1/2020	3.5000	%		35,000,000

Balances as of December 31, 2010				$	180,000,000

In September 2010, Main Street entered into an $85 million, three-year credit facility (the "Credit Facility") with a group of bank lenders, and in January 2011, Main Street expanded the Credit Facility from $85 million to $100 million. The purpose of the Credit Facility is to provide additional liquidity in support of future investment and operational activities. The revisions to the Credit Facility provide several benefits to Main Street, including (i) an expansion of the total committed facility size to $100 million compared with Main Street's prior $30 million credit facility, (ii) increased advance rates applicable to Main Street's eligible investments, (iii) the addition of new lenders which further diversifies the Main Street lending group to a total of six participants, and (iv) an extension of the maturity date to September 20, 2013. The accordion feature of the Credit Facility allows us to seek up to $150 million of total commitments from new or existing lenders on the same terms and conditions as the existing commitments. Borrowings under the Credit Facility bear interest, subject to Main Street's election, on a per annum basis equal to (i) the applicable LIBOR rate plus 2.50% or (ii) the applicable base rate plus 1.50%. Main Street pays unused commitment fees of 0.375% per annum on the average unused lender commitments under the Credit Facility. The Credit Facility is secured by a first lien on the assets of MSCC and its subsidiaries, excluding the assets of the Funds. The Credit Facility contains certain affirmative and negative covenants, including but not limited to: (i) maintaining an interest coverage ratio of at least 2.0 to 1.0, (ii) maintaining an asset coverage ratio of at least 2.5 to 1.0, and

(iii) maintaining a minimum tangible net worth. At December 31, 2010, Main Street had $39 million in borrowings outstanding under the Credit Facility and recognized $519,439 in interest expense for the year ended December 31, 2010 related to the Credit Facility. As of December 31, 2010, Main Street was in compliance with all financial covenants of the Credit Facility.

	Years Ended December 31,

Per Share Data:	2010			2009
Net asset value at beginning of period	$	11.96		$	12.20
Net investment income(1)(3)		1.16			0.92
Net realized loss from investments(1)(2)(3)		(0.17	)		(0.78	)
Net change in unrealized appreciation (depreciation)(1)(2)(3)		1.14			0.82
Income tax (provision) benefit(1)(2)(3)		(0.05	)		0.23
Bargain purchase gain(1)		0.30			—

Net increase in net assets resulting from operations(1)		2.38			1.19
Net decrease in net assets from dividends paid to stockholders		(1.50	)		(1.50	)
Impact of monthly dividend declared as of December 31, 2008 but paid on January 15, 2009		—			0.13
Accretive effect of public stock offerings (issuing shares above NAV per share)		0.49			—
Accretive effect of Exchange Offer		0.22			—
Adjustment to investment in Investment Manager in connection with Exchange Offer Transactions		(0.73	)		—
Accretive effect of DRIP issuance (issuing shares above NAV per share)		0.08			—
Other (4)		0.16			(0.06	)

Net asset value at December 31, 2010 and 2009	$	13.06		$	11.96

Market value at December 31, 2010 and 2009	$	18.19		$	16.12
Shares outstanding at December 31, 2010 and 2009		18,797,444			10,842,447

Main Street paid monthly dividends of $0.125 per share for each month beginning January 2010 through December 2010, totaling $23.9 million, or $1.50 per share, for the period. For tax purposes, the 2010 dividends were comprised of (i) ordinary income totaling approximately $1.22 per share, (ii) long term capital gain totaling approximately $0.27 per share, and (iii) qualified dividend income totaling approximately $0.01 per share. Main Street estimates that it generated undistributed taxable income of approximately $1.6 million, or $0.09 per share, during 2010 that will be carried forward toward distributions paid in 2011. For the year ended December 31, 2009, Main Street paid dividends of approximately $14.9 million, or $1.50 per share, for the period. For tax purposes, the monthly dividend paid in January 2009 was applied against the calendar year 2008 taxable income distribution since that dividend was declared and accrued prior to December 31, 2008. For tax purposes, the 2009 dividends were comprised of ordinary income totaling approximately $1.22 per share and long term capital gain totaling approximately $0.16 per share. Ordinary dividend distributions from a RIC do not qualify for the 15% maximum tax rate on dividend income from domestic corporations and qualified foreign corporations, except to the extent that the RIC received the income in the form of qualifying dividends from domestic corporations and qualified foreign corporations (which Main Street did not receive during the 2010 year).

MSCC has elected to be treated for federal income tax purposes as a RIC. As a RIC, MSCC generally will not pay corporate-level federal income taxes on any net ordinary income or capital gains that MSCC distributes to its stockholders as dividends. MSCC must generally distribute at least 90% of its investment company taxable income to qualify for pass-through tax treatment and maintain its RIC status. As part of maintaining RIC status, undistributed taxable income (subject to a 4% excise tax) pertaining to a given fiscal year may be distributed up to 12 months subsequent to the end of that fiscal year, provided such dividends are declared prior to the filing of the federal income tax return for the prior year.

The Taxable Subsidiaries hold certain portfolio investments for Main Street. The Taxable Subsidiaries are consolidated with Main Street for financial reporting purposes, and the portfolio investments held by the Taxable Subsidiaries are included in Main Street's consolidated financial statements. The principal purpose of the Taxable Subsidiaries are to permit Main Street to hold equity investments in portfolio companies which

are "pass through" entities for tax purposes in order to comply with the "source income" requirements contained in the RIC tax provisions of the Code. The Taxable Subsidiaries are not consolidated with Main Street for income tax purposes and may generate income tax expense or income tax benefit as a result of their ownership of various portfolio investments. This income tax expense or benefit, if any, is reflected in Main Street's Consolidated Statement of Operations. For the year ended December 31, 2010, Main Street recognized an income tax provision of $0.9 million primarily consisting of deferred tax expense related to net unrealized appreciation on certain portfolio investments held by the Taxable Subsidiaries.

Main Street's provision for income taxes, including the Taxable Subsidiaries, was comprised of the following:

Listed below is a reconciliation of "Net Increase in Net Assets Resulting From Operations" to taxable income and to total distributions declared to common stockholders for the years ended December 31, 2010 and 2009.

	Years Ended December 31,

	2010			2009
	(estimated)(1)
Net increase (decrease) in net assets resulting from operations	$	39,970,351		$	11,956,229
Share-based compensation expense		1,488,709			1,068,397
Net change in unrealized (appreciation) depreciation on investments		(19,639,414	)		(8,242,107	)
Bargain purchase gain		(4,890,582	)		—
Income tax provision (benefit)		940,634			(2,289,841	)
Pre-tax book loss (income) of Taxable Subsidiaries not consolidated for tax purposes		5,741,951			8,773,006
Book income and tax income differences, including debt origination, structuring fees and realized gains		963,325			270,444

Taxable income		24,574,974			11,536,128
Taxable income earned in prior year and carried forward for distribution in current year		930,925			3,129,727
Ordinary taxable income earned in current period and carried forward for distribution		(1,605,990	)		(930,925	)

Total distributions to common stockholders	$	23,899,909		$	13,734,930

The net deferred tax asset at December 31, 2010 and 2009 was $2.0 million and $2.7 million, respectively, and primarily related to timing differences from recognition of unrealized and realized depreciation from debt and equity investments in portfolio investments as well as timing differences from taxable income from equity investments in portfolio companies which are "pass through" entities for tax purposes. Management believes that the realization of the deferred tax asset is more likely than not based on expectations as to future taxable income and scheduled reversals of temporary differences. Accordingly, Main Street did not record a valuation allowance related to its deferred tax asset at December 31, 2010.

On January 7, 2010, MSCC consummated the Exchange Offer to exchange 1,239,695 shares (the "Exchange Shares") of its common stock for approximately 88% of the total dollar value of the limited partner interests in MSC II. Pursuant to the terms of the Exchange Offer, 100% of the membership interests in MSC II GP were also transferred to MSCC for no consideration. MSC II commenced operations in January 2006, is an investment fund that operates as an SBIC and is managed by the Investment Manager. The Exchange Offer was applicable to all MSC II limited partner interests except for any limited partner interests owned by affiliates of MSCC, including any limited partner interests owned by officers or directors of MSCC. The Exchange Offer was formally approved by the SBA prior to closing. The Exchange Shares were subject to a one-year contractual lock-up from the Exchange Offer closing date. An approximately 12% minority ownership in the total dollar value of the MSC II limited partnership interests remains outstanding, including approximately 5% owned by affiliates of MSCC.

The Exchange Offer was accounted for under the acquisition method of accounting in accordance with ASC 805. Accordingly, the purchase price was preliminarily allocated to the acquired assets and liabilities based on their estimated fair values at the Exchange Offer acquisition date as summarized in the following table. The fair value of the MSC II net assets acquired exceeded the fair value of the stock consideration issued, resulting in a bargain purchase gain that was recorded by Main Street in the period that the Exchange Offer was completed.


Value of the stock consideration issued for limited partner interests acquired	$	19,934,296	(1)
Fair value of noncontrolling limited partner interests		3,396,005	(2)

Total stock consideration and noncontrolling interest value		23,330,301
Fair value of MSC II assets and liabilities on January 7, 2010:
Cash		2,489,920
Debt investments acquired at fair value		64,925,164
Equity investments acquired at fair value		14,930,614
Other assets		808,560
SBIC debentures at fair value		(53,139,092	)
Deferred tax liability assumed		(82,827	)
Other liabilities		(1,519,608	)

Total fair value of MSC II net assets		28,412,731

Bargain purchase gain		5,082,430
Transaction costs associated with the Exchange Offer		(191,848	)

Bargain purchase gain, net of transaction costs	$	4,890,582

Consummation of the Exchange Offer Transactions provides Main Street with access to additional long-term, low-cost leverage capacity through the SBIC program. The American Recovery and Reinvestment Act of 2009 enacted in February 2009 (the "Stimulus Bill") increased the maximum amount of combined SBIC leverage (or SBIC leverage cap) to $225 million for affiliated SBIC funds from the previous SBIC leverage cap of approximately $137 million. Since the increase in the SBIC leverage cap applies to affiliated SBIC funds, Main Street is required to allocate such increased borrowing capacity between MSMF and MSC II. Main Street currently has access to an incremental $45 million in SBIC leverage capacity, subject to the required capitalization of each of the Funds, in addition to the $180 million of existing SBIC leverage at the Funds.

The following represents actual operating results for the year ended December 31, 2010 and pro forma operating results for the year ended December 31, 2009. The pro forma operating results assume the Exchange Offer Transactions had been completed as of the beginning of the 2009 calendar year:

In August 2010, Main Street completed a public stock offering of 3,220,000 shares of common stock, including the underwriters' exercise of the over-allotment option, at a price to the public of $15.00 per share, resulting in total net proceeds of approximately $45.8 million, after deducting underwriters' commissions and offering costs.

In January 2010, Main Street completed a public stock offering of 2,875,000 shares of common stock, including the underwriters' exercise of the over-allotment option, at a price to the public of $14.75 per share, resulting in total net proceeds of approximately $40.1 million, after deducting underwriters' commissions and offering costs.

On November 13, 2008, Main Street announced that its Board of Directors authorized its officers, in their discretion and subject to compliance with the 1940 Act and other applicable laws, to purchase on the open market or in privately negotiated transactions, an amount up to $5 million of the outstanding shares of Main Street's common stock at prices per share not to exceed Main Street's last reported net asset value per share. The repurchase program terminated as of December 31, 2009. From January through September of 2009, Main Street purchased 164,544 shares in connection with the repurchase program at a weighted average cost of $9.82 per share.

Main Street's DRIP provides for the reinvestment of dividends on behalf of its stockholders, unless a stockholder has elected to receive dividends in cash. As a result, if Main Street declares a cash dividend, the company's stockholders who have not "opted out" of the DRIP by the dividend record date will have their cash dividend automatically reinvested into additional shares of MSCC common stock. Main Street has the option to satisfy the share requirements of the DRIP through the issuance of shares of common stock or through open market purchases of common stock by the DRIP plan administrator. Newly issued shares will be valued based upon the final closing price of MSCC's common stock on the valuation date determined for

each dividend by Main Street's Board of Directors. Shares purchased in the open market to satisfy the DRIP requirements will be valued based upon the average price of the applicable shares purchased by the DRIP plan administrator, before any associated brokerage or other costs. Main Street's DRIP is administered by its transfer agent on behalf of Main Street's record holders and participating brokerage firms. Brokerage firms and other financial intermediaries may decide not to participate in Main Street's DRIP but may provide a similar dividend reinvestment plan.

For the year ended December 31, 2010, $8.2 million of the total $23.9 million in dividends paid to stockholders represented DRIP participation. During this period, Main Street satisfied the DRIP participation requirements with the purchase of 35,572 shares of common stock in the open market and the issuance of 478,731 new shares. For the year ended December 31, 2009, $5.4 million of the total $14.9 million in dividends paid to stockholders represented DRIP participation. Main Street satisfied the DRIP participation requirements with the purchase of 169,742 shares of common stock in the open market and the issuance of 271,906 new shares. The shares disclosed above relate only to Main Street's DRIP and exclude any activity related to broker-managed dividend reinvestment plans.

Main Street accounts for its share-based compensation plans using the fair value method, as prescribed by ASC 718, Compensation — Stock Compensation. Accordingly, for restricted stock awards, Main Street measured the grant date fair value based upon the market price of its common stock on the date of the grant and will amortize this fair value to share-based compensation expense over the requisite service period or vesting term.

On July 1, 2010, Main Street's Board of Directors approved the issuance of 149,357 shares of restricted stock to Main Street employees pursuant to the Main Street Capital Corporation 2008 Equity Incentive Plan. These shares will vest over a four-year period from the grant date and will be expensed over the four-year service period starting on the grant date. On July 1, 2009, Main Street's Board of Directors approved the issuance of 99,312 shares of restricted stock to Main Street employees pursuant to the Main Street Capital Corporation 2008 Equity Incentive Plan. These shares are vesting over a four-year period from the grant date and are being expensed over the four-year service period starting on the grant date. As of December 31, 2010, there were 1,506,005 shares of restricted stock available for issuance to employees under the Main Street Capital Corporation 2008 Equity Incentive Plan.

On July 1, 2010, a total of 7,920 shares of restricted stock was issued to Main Street's independent directors pursuant to the Main Street Capital Corporation 2008 Non-Employee Director Restricted Stock Plan. These shares will vest on the day immediately preceding Main Street's 2011 annual meeting of stockholders and are being expensed over a one-year service period starting on the grant date. On July 1, 2009, a total of 8,512 shares of restricted stock was issued to Main Street's independent directors pursuant to the Main Street Capital Corporation 2008 Non-Employee Director Restricted Stock Plan. These shares vested on the day immediately preceding Main Street's June 2010 annual meeting of stockholders and were expensed over a one-year service period starting on the grant date. As of December 31, 2010, there were 163,568 shares of restricted stock available for issuance to non-employee directors under the Main Street Capital Corporation 2008 Non-Employee Director Restricted Stock Plan.

For the years ended December 31, 2010 and 2009, Main Street recognized total share-based compensation expense of $1.5 million and $1.1 million, respectively, related to the restricted stock issued to Main Street employees and Main Street's independent directors.

As of December 31, 2010, there was $4.0 million of total unrecognized compensation expense related to Main Street's non-vested restricted shares. This compensation expense is expected to be recognized over a weighted-average period of approximately 2.7 years.

At December 31, 2010, Main Street had five outstanding commitments to fund unused revolving loans for up to $9.0 million in total.

Listed below are the supplemental cash flow disclosures for the years ended December 31, 2010, 2009, and 2008:

As discussed further in Note D to the accompanying consolidated financial statements, subsequent to the completion of the Formation Transactions, the Investment Manager is a wholly owned portfolio company of MSCC. At December 31, 2010 and 2009, the Investment Manager had a receivable of $15,124 and $217,422, respectively, with MSCC related to net cash expenses incurred by the Investment Manager required to support Main Street's business.

During January 2011, Main Street closed an expansion of the Credit Facility from $85 million to $100 million. The $15 million increase in total commitments pursuant to an accordion feature under the Credit Facility relates to a new lender relationship which further diversifies the Main Street lending group to a total of six participants. The accordion feature of the Credit Facility allows Main Street to seek up to $150 million of total commitments from new or existing lenders on the same terms and conditions as the existing commitments. The increase in total commitments under the Credit Facility provides Main Street with access to additional financing capacity in support of its future investment and operational activities.

We have audited in accordance with the standards of the Public Company Accounting Oversight Board (United States) the consolidated financial statements of Main Street Capital Corporation referred to in our report dated March 11, 2011, which is included in the annual report on Form 10-K. Our audits of the basic financial statements include the financial statement schedule listed in the index appearing under Item 15(2) which is the responsibility of the Company's management. In our opinion, this financial statement schedule, when considered in relation to the basic financial statements taken as a whole, presents fairly, in all material respects, the information set forth therein.

MAIN STREET CAPITAL CORPORATION

Schedule of Investments in and Advances to Affiliates
Year ended December 31, 2010

Company		Investments(1)	Amount of Interest or Dividends Credited to Income(2)		December 31, 2009 Value		Gross Additions(3)		Gross Reductions(4)		December 31, 2010 Value

CONTROL INVESTMENTS
Advantage Millwork		12% Secured Debt	$	—	$	—	$	3,000,000	$	3,000,000	$	—
	Company, Inc.	Warrants		—		—		—		—		—

Café Brazil, LLC		12% Secured Debt	$	304,530		2,500,000		—		500,000		2,000,000
		Member Units		56,440		1,520,000		720,000		—		2,240,000

CBT Nuggets, LLC		14% Secured Debt		413,472		1,680,000		1,112,180		—		2,792,180
		10% Secured Debt		121,062		915,000		610,000		750,000		775,000
		Member Units		578,022		1,500,000		1,950,000		—		3,450,000

California Healthcare		12% Secured Debt		320,763		—		2,519,933		—		2,519,933
	Medical Billing, Inc.	12% Current/6% PIK Secured Debt		780,638		—		4,610,215		144,400		4,465,815
		Warrants		—		—		3,280,333		—		3,280,333
		Common Stock		—		—		2,066,667		576,667		1,490,000

Ceres Management, LLC		14% Secured Debt		579,199		2,377,388		1,587,180		—		3,964,568
	(Lambs)	Class B Member Units		144,619		218,395		1,290,216		—		1,508,611
		Member Units		—		920,000		613,333		433,333		1,100,000

Condit Exhibits, LLC		13% Current/5% PIK Secured Debt		820,220		2,622,107		2,061,750		64,198		4,619,659
		Warrants		—		30,000		20,000		—		50,000

Currie Acquisitions, LLC		12% Secured Debt		656,793		—		3,971,699		—		3,971,699
		Warrants		—		—		2,566,204		226,000		2,340,204

Gulf Manufacturing, LLC		8% Secured Debt		237,400		1,200,000		3,100,000		680,000		3,620,000
		13% Secured Debt		294,024		998,095		1,497,070		820,000		1,675,165
		9% PIK Secured Debt		—		—		1,420,784		—		1,420,784
		Warrants		—		1,080,000		1,620,000		2,700,000		—
		Member Units		236,220		2,360,000		4,542,187		1,032,187		5,870,000

Harrison Hydra-Gen, Ltd.		12% Secured Debt		722,127		—		5,255,101		—		5,255,101
		Preferred Stock		—		—		1,000,000		—		1,000,000
		Warrants		—		—		717,640		—		717,640

Hawthorne Customs &		Member Units		—		840,000		410,000		—		1,250,000
	Dispatch Services, LLC

Hydratec Holdings, LLC		12.5% Secured Debt		322,533		2,956,635		38,609		2,995,244		—
		Prime plus 1% Secured Debt		16,075		338,667		11,333		350,000		—
		Member Units		219,064		6,620,000		2,995,244		437,333		9,177,911

Indianapolis Aviation		12% Secured Debt		615,866		—		4,350,000		—		4,350,000
	Partners, LLC	Warrants		—		—		1,570,286		—		1,570,286

Jensen Jewelers of		Prime plus 2% Secured Debt		140,980		1,044,000		1,566,000		350,000		2,260,000
	Idaho, LLC	13% Current/6% PIK Secured Debt		514,685		1,067,437		1,682,256		404,797		2,344,896
		Member Units		107,875		290,000		770,000		—		1,060,000

Mid-Columbia Lumber		Prime Plus 1% Secured Debt		46,294		—		1,250,000		—		1,250,000
	Products, LLC	12% Secured Debt		568,263		—		3,900,000		—		3,900,000
		Warrants		—		—		740,000		—		740,000
		Member Units		—		—		770,000		—		770,000

NAPCO Precast, LLC		Prime plus 2% Secured Debt		315,506		3,384,615		—		—		3,384,615
		18% Secured Debt		1,103,522		5,923,077		—		—		5,923,077
		Member Units		10,000		5,220,000		—		880,000		4,340,000

NTS Holdings, Inc.		12% Secured Debt		798,302		—		5,963,931		—		5,963,931
		Preferred Stock		779,913		—		10,635,273		—		10,635,273
		Common Stock		70,000		—		776,000		—		776,000

OMi Holdings, Inc.		12% Secured Debt		1,279,240		6,298,395		4,218,429		400,000		10,116,824
		Common Stock		—		270,000		230,000		—		500,000

Company		Investments(1)	Amount of Interest or Dividends Credited to Income(2)		December 31, 2009 Value		Gross Additions(3)		Gross Reductions(4)		December 31, 2010 Value

PPL RVs, Inc.		18% Secured Debt		772,678		—		6,165,058		—		6,165,058
		Common Stock		—		—		2,150,000		—		2,150,000

Quest Design &		10% Secured Debt		—		200,000		—		200,000		—
	Production LLC	0% Secured Debt		—		—		—		—		—
		Warrants		—		—		—		—		—
		Warrants		—		—		—		—		—

The MPI Group, LLC		4.5% Current/4.5% PIK Secured Debt		35,689		—		501,176		—		501,176
		6% Current/6% PIK Secured Debt		619,190		—		4,935,760		—		4,935,760
		Warrants		—		—		895,943		705,943		190,000

Thermal & Mechanical		13% Current/5% PIK Secured Debt		1,071,785		3,301,405		2,273,815		—		5,575,220
	Equipment, LLC	Prime plus 2% Secured Debt		119,863		1,043,471		695,681		—		1,739,152
		Warrants		—		600,000		1,340,000		—		1,940,000

Uvalco Supply, LLC		Member Units		—		1,390,000		170,000		—		1,560,000

Vision Interests, Inc.		13% Secured Debt		414,557		—		8,762,314		—		8,762,314
		Common Stock		—		—		—		—		—
		Warrants		—		—		10		10		—

Ziegler's NYPD, LLC		Prime plus 2% Secured Debt		93,101		595,252		398,685		—		993,937
		13% Current/5% PIK Secured Debt		871,566		2,775,643		2,094,117		117,672		4,752,088
		Warrants		2,000		360,000		240,000		130,000		470,000

Other				352,690		1,961,085		2,483,699		22,600		4,422,184

Income from Control Investments disposed of during the year				—		—		—		—		—

		Total — Control	$	17,526,766	$	66,400,667	$	126,116,111	$	17,920,384	$	174,596,394

AFFILATE INVESTMENTS
Advantage Millwork		12% Secured Debt	$	—	$	1,200,000	$	—	$	1,200,000	$	—
	Company, Inc.	Warrants		—		—		—		—		—

American Sensor		Prime plus .5% Secured Debt		381,246		3,800,000		517,157		803,044		3,514,113
	Technologies, Inc.	Warrants		—		820,000		1,010,000		—		1,830,000

Audio Messaging		12% Secured Debt		864,365		—		7,650,299		224,000		7,426,299
	Solutions, LLC	Warrants		—		—		1,280,000		—		1,280,000

California Healthcare		12% Secured Debt		—		1,275,400		—		1,275,400		—
	Medical Billing, Inc.	12% Current/6% PIK Secured Debt		—		842,583		—		842,583		—
		Warrants		—		1,280,000		—		1,280,000		—
		Common Stock		—		1,180,000		—		1,180,000		—

Compact Power Equipment		12% Secured Debt		368,505		1,778,702		1,342,248		—		3,120,950
	Centers, LLC	Member Units		—		688		459		—		1,147

DrillingInfo, Inc.		12% Secured Debt		1,171,336		—		7,770,000		—		7,770,000
		Warrants		—		—		4,010,000		—		4,010,000
		Common Stock		—		—		1,710,325		—		1,710,325

East Teak
	Fine Hardwoods, Inc.	Common Stock		1,225		—		861,538		531,538		330,000

Houston Plating &		Prime Plus 2%		15,750		300,000		—		—		300,000
	Coatings, LLC	Member Units		367,500		3,565,000		—		540,000		3,025,000

Indianapolis Aviation		12% Secured Debt		—		2,444,759		—		2,444,759		—
	Partners, LLC	Warrants		—		677,571		—		677,571		—

IRTH Holdings, LLC		12% Secured Debt		60,000		—		5,891,126		—		5,891,126
		Member Units		—		—		850,000		—		850,000

KBK Industries, LLC		14% Secured Debt		852,597		3,853,825		1,388,174		—		5,241,999
		10% Secured Debt		833		93,750		31,250		125,000		—
		10% Secured Debt		64,050		450,000		439,940		375,000		514,940
		Member Units		12,066		460,000		1,330,333		—		1,790,333

Laurus Healthcare, LP,		13% Secured Debt		358,155		2,275,000		1,050,000		525,000		2,800,000
		Warrants		—		4,400,000		1,270,000		1,050,000		4,620,000

Company		Investments(1)	Amount of Interest or Dividends Credited to Income(2)		December 31, 2009 Value		Gross Additions(3)		Gross Reductions(4)		December 31, 2010 Value

National Trench Safety, LLC		10% PIK Debt		—		447,203		—		447,203		—
		Member Units		—		700,000		—		700,000		—

Lighting Unlimited, LLC		Prime Plus 1% Secured Debt		98,262		—		1,179,935		233,337		946,598
		12% Current/2% PIK Secured Debt		266,099		—		1,723,326		—		1,723,326
		Warrants		—		—		60,000		60,000		—

Merrick Systems, Inc.		13% Secured Debt		335,631		—		2,540,849		—		2,540,849
		Warrants		—		—		450,000		—		450,000

Olympus Building		12% Secured Debt		412,727		1,830,000		1,220,000		—		3,050,000
	Services, Inc.	12% Current/3% PIK Secured Debt		164,488		342,782		1,120,234		479,015		984,001
		Warrants		—		480,000		450,000		—		930,000

OPI International LTD		12% Secured Debt		233,885		—		8,789,573		—		8,789,573
		Warrants		—		—		500,000		—		500,000

Pulse Systems, LLC		Warrants		—		340,000		—		340,000		—

Schneider Sales		13% Secured Debt		459,557		1,927,700		1,361,426		2,289,126		1,000,000
	Management, LLC	Warrants		—		—		—		—		—

Vision Interests, Inc.		13% Secured Debt		—		3,220,000		—		3,220,000		—
		Warrants		—		—		—		—		—
		Common Stock		—		—		—		—		—

Walden Smokey Point, Inc.		14% Current/4% PIK Secured Debt		1,648,075		4,915,014		3,746,108		8,661,122		—
		Common Stock		14,000		1,240,000		1,380,000		—		2,620,000

WorldCall, Inc.		13% Secured Debt		85,176		646,225		—		—		646,225
		Common Stock		—		100,000		—		100,000		—

Other				15,094		—		—		—		—

Income from Affiliate Investments disposed of during the year				—		—		—		—		—

		Total — Affiliate Investments	$	8,250,622	$	46,886,202	$	62,924,300	$	29,603,698	$	80,206,804

This schedule should be read in conjunction with Main Street's Consolidated and Combined Financial Statements, including the Consolidated and Combined Schedule of Investments and Notes to the Consolidated Financial Statements.

(1): The principal amount, the ownership detail for equity investments and if the investment is income producing is shown in the Consolidated and Combined Schedule of Investments.
(2): Represents the total amount of interest, fees or dividends credited to income for the portion of the year an investment was included in Control or Affiliate categories, respectively. For investments transferred between Control and Affiliate categories during the year, any income related to the time period it was in the category other than the one shown at year end is included in "Income from Investments disposed of during the year".
(3): Gross additions include increases in the cost basis of investments resulting from new portfolio investment, follow on investments and accrued PIK interest, and the exchange of one or more existing securities for one or more new securities. Gross Additions also include net increases in unrealized appreciation or net decreases in unrealized depreciation as well as the movement of an existing portfolio company into this category and out of a different category.
(4): Gross reductions include decreases in the cost basis of investments resulting from principal repayments or sales and the exchange of one or more existing securities for one or more new securities. Gross reductions also include net increases in unrealized depreciation or net decreases in unrealized appreciation as well as the movement of an existing portfolio company out of this category and into a different category.

Item 9. Changes in and Disagreements with Accountants on Accounting and Financial Disclosure

(a) Evaluation of Disclosure Controls and Procedures. As of the end of the period covered by this annual report on Form 10-K, our Chief Executive Officer, Chief Financial Officer, Chief Compliance Officer and Chief Accounting Officer conducted an evaluation of our disclosure controls and procedures (as defined in Rules 13a-15(e) of the Securities Exchange Act of 1934). Based upon this evaluation, our Chief Executive Officer, Chief Financial Officer, Chief Compliance Officer and Chief Accounting Officer concluded that our disclosure controls and procedures are effective to allow timely decisions regarding required disclosure of any material information relating to us that is required to be disclosed by us in the reports we file or submit under the Securities Exchange Act of 1934.

(b) Management's Report on Internal Control Over Financial Reporting. The management of Main Street Capital Corporation and its subsidiaries (the Company) is responsible for establishing and maintaining adequate internal control over financial reporting, as such term is defined in Exchange Act Rules 13a-15(f). Under the supervision and with the participation of management, including the Chief Executive Officer and Chief Financial Officer, the Company conducted an evaluation of the effectiveness of the Company's internal control over financial reporting based on the criteria established in Internal Control — Integrated Framework issued by the Committee of Sponsoring Organizations of the Treadway Commission (COSO). Based on the Company's evaluation under the framework in Internal Control — Integrated Framework, management concluded that the Company's internal control over financial reporting was effective as of December 31, 2010. Grant Thornton, LLP, the Company's independent registered public accounting firm, has issued an attestation report on the effectiveness of the Company's internal control over financial reporting as of December 31, 2010, as stated in its report which is included herein.

(c) Attestation Report of the Registered Public Accounting Firm. Our independent registered public accounting firm, Grant Thornton LLP, has issued an attestation report on the effectiveness of our internal control over financial reporting, which is set forth above under the heading "Report of Independent Registered Public Accounting Firm" in Item 8.

(d) Changes in Internal Control over Financial Reporting. There have been no changes in our internal control over financial reporting (as defined in Rule 13a-15(f) of the Securities Exchange Act of 1934) that occurred during our most recently completed fiscal quarter, that have materially affected, or are reasonably likely to materially affect, our internal control over financial reporting.

The information required by this Item will be contained in the definitive proxy statement relating to our 2010 annual meeting of stockholders (the "Proxy Statement") under the headings "Election of Directors," "Corporate Governance," "Executive Officers" and "Section 16(a) Beneficial Ownership Reporting Compliance," to be filed with the Securities and Exchange Commission on or prior to April 30, 2011, and is incorporated herein by reference.

We have adopted a code of business conduct and ethics that applies to directors, officers and employees of Main Street. This code of ethics is published on our Web site at www.mainstcapital.com. We intend to

disclose any future amendments to, or waivers from, this code of conduct within four business days of the waiver or amendment through a Web site posting.

The information required by this Item will be contained in the Proxy Statement under the headings "Compensation of Executive Officers," "Compensation of Directors," "Compensation Discussion and Analysis," "Compensation Committee Interlocks and Insider Participation" and "Compensation Committee Report," to be filed with the Securities and Exchange Commission on or prior to April 30, 2011, and is incorporated herein by reference.

Item 12. Security Ownership of Certain Beneficial Owners and Management and Related Stockholder Matters

The following table provides information regarding our equity compensation plans as of December 31, 2010:

The other information required by this Item will be contained in the Proxy Statement under the headings "Security Ownership of Certain Beneficial Owners and Management," to be filed with the Securities and Exchange Commission on or prior to April 30, 2011, and is incorporated herein by reference.

Item 13. Certain Relationships and Related Transactions, and Director Independence

The information required by this Item will be contained in the Proxy Statement under the headings "Certain Relationships and Related Transactions" and "Corporate Governance," to be filed with the Securities and Exchange Commission on or prior to April 30, 2011, and is incorporated herein by reference.

The information required by this Item will be contained in the Proxy Statement under the heading "Independent Registered Public Accounting Firm," to be filed with the Securities and Exchange Commission on or prior to April 30, 2011, and is incorporated herein by reference.

The following documents are filed or incorporated by reference as part of this Annual Report:

The following exhibits are filed as part of this report or hereby incorporated by reference to exhibits previously filed with the SEC:

Exhibit Number			Description

	3.1*		Articles of Amendment and Restatement of Main Street Capital Corporation (previously filed as Exhibit (a) to Main Street Capital Corporation's Pre-Effective Amendment No. 2 to the Registration Statement on Form N-2 filed on August 15, 2007 (Reg. No. 333-142879))
	3.2*		Amended and Restated Bylaws of Main Street Capital Corporation (previously filed as Exhibit 99.1 to Main Street Capital Corporation's Current Report on Form 8-K filed on May 2, 2008 (File No. 1-33723))
	4.1*		Form of Common Stock Certificate (previously filed as Exhibit (d) to Main Street Capital Corporation's Pre-Effective Amendment No. 2 to the Registration Statement on Form N-2 filed on August 15, 2007 (Reg. No. 333-142879))
	4.2*		Dividend Reinvestment Plan (previously filed as Exhibit 4.2 to Main Street Capital Corporation's Annual Report on Form 10-K for the year ended December 31, 2007 filed on March 21, 2008 (File. No. 1-33723))
	4.3*		Main Street Mezzanine Fund, LP SBIC debentures guaranteed by the SBA (previously filed as Exhibit (f)(1) to Main Street Capital Corporation's Pre-Effective Amendment No. 1 to the Registration Statement on Form N-2 filed on June 22, 2007 (Reg. No. 333-142879))
	4.4*		Main Street Capital II, LP SBIC debentures guaranteed by the SBA (see Exhibit (f)(1) to Pre-Effective Amendment No. 1 to Form N-2 of Main Street Capital Corporation filed with the SEC on June 22, 2007 for a substantially identical copy of the form of debentures)
	10.1*		Amended and Restated Credit Agreement dated September 20, 2010 (previously filed as Exhibit 10.1 to Main Street Capital Corporation's Current Report on Form 8-K filed September 21, 2010 (File No. 1-33723))

Exhibit Number			Description

	10.2*		Amended and Restated General Security Agreement dated September 20, 2010 (previously filed as Exhibit 10.2 to Main Street Capital Corporation's Current Report on Form 8-K filed September 21, 2010 (File No. 1-33723))
	10.3*		Amended and Restated Custodial Agreement dated September 20, 2010 (previously filed as Exhibit 10.3 to Main Street Capital Corporation's Current Report on Form 8-K filed September 21, 2010 (File No. 1-33723))
	10.4*		Amended and Restated Equity Pledge Agreement dated September 20, 2010 (previously filed as Exhibit 10.4 to Main Street Capital Corporation's Current Report on Form 8-K filed September 21, 2010 (File No. 1-33723))
	10.5*		Supplement and Joinder Agreement dated January 7, 2011 (previously filed as Exhibit 10.1 to Main Street Capital Corporation's Current Report on Form 8-K filed January 10, 2011 (File No. 1-33723))
	10.6*		Form of Amended and Restated Investment Advisory Agreement by and between Main Street Capital Partners, LLC and Main Street Mezzanine Fund, LP (previously filed as Exhibit (g)(1) to Main Street Capital Corporation's Pre-Effective Amendment No. 1 to the Registration Statement on Form N-2 filed on June 22, 2007 (Reg. No. 333-142879))
	10.7*		Investment Management/Advisory Agreement by and between Main Street Capital Partners, LLC, Main Street Capital II, LP and Main Street Capital II GP, LLC (previously filed as Exhibit (g)(2) to Main Street Capital Corporation's Pre-Effective Amendment No. 1 to the Registration Statement on Form N-2 filed on June 22, 2007 (Reg. No. 333-142879))
	10.8*†		Main Street Capital Corporation 2008 Equity Incentive Plan (previously filed as Exhibit 10.1 to Main Street Capital Corporation's Quarterly Report on Form 10-Q for the quarter ended June 30, 2009 filed on August 7, 2009 (File No. 1-33723))
	10.9*†		Main Street Capital Corporation 2008 Non-Employee Director Restricted Stock Plan (previously filed as Exhibit 4.5 to Main Street Capital Corporation's Registration Statement on Form S-8 filed on June 20, 2008 (Reg. No. 333-151799))
	10.10*		Custodian Agreement (previously filed as Exhibit (j) to Main Street Capital Corporation's Pre-Effective Amendment No. 3 to the Registration Statement on Form N-2 filed on September 21, 2007 (Reg. No. 333-142879))
	10.11*†		Form of Confidentiality and Non-Compete Agreement by and between Main Street Capital Corporation and Vincent D. Foster (previously filed as Exhibit (k)(12) to Main Street Capital Corporation's Pre-Effective Amendment No. 3 to the Registration Statement on Form N-2 filed on September 21, 2007 (Reg. No. 333-142879))
	10.12*†		Form of Indemnification Agreement by and between Main Street Capital Corporation and each executive officer and director (previously filed as Exhibit (k)(13) to Main Street Capital Corporation's Pre-Effective Amendment No. 3 to the Registration Statement on Form N-2 filed on September 21, 2007 (Reg. No. 333-142879))
	10.13*		Support Services Agreement effective as of October 2, 2007 by and between Main Street Capital Corporation and Main Street Capital Partners, LLC (previously filed as Exhibit (k)(16) to Main Street Capital Corporation's Pre-Effective Amendment No. 1 to the Registration Statement on Form N-2 filed on January 30, 2009 (Reg. No. 333-155806))
	14.1*		Code of Ethics (previously filed as Exhibit (r) to Main Street Capital Corporation's Pre-Effective Amendment No. 2 to the Registration Statement on Form N-2 filed on August 15, 2007 (Reg. No. 333-142879))
	21.1		List of Subsidiaries
	23		Consent of Grant Thornton, LLP, independent registered public accounting firm

Pursuant to the requirements of Section 13 or 15(d) of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.

Pursuant to the requirements of the Securities Exchange Act of 1934, this report has been signed below by the following persons on behalf of the registrant and in the capacities and on the dates indicated.


(Mark One)
þ		ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934
		For the fiscal year ended December 31, 2010
OR
o		TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934
		For the transition period from to


Maryland (State or other jurisdiction of incorporation or organization)		41-2230745 (I.R.S. Employer Identification No.)
1300 Post Oak Boulevard, Suite 800 Houston, TX (Address of principal executive offices)		77056 (Zip Code)

Title of Each Class		Name of Each Exchange on Which Registered

Common Stock, par value $0.01 per share		New York Stock Exchange


Large accelerated filer o	Accelerated filer þ	Non-accelerated filer o	Smaller reporting company o
	(Do not check if a smaller reporting company)

		December 31, 2010					December 31, 2009

Investment Rating		Investments at Fair Value		Percentage of Total Portfolio			Investments at Fair Value		Percentage of Total Portfolio
		(dollars in thousands)
	1	$	52,147		15.0	%	$	14,509		10.3	%
	2		153,408		44.2	%		59,116		42.0	%
	3		122,249		35.3	%		57,578		40.9	%
	4		17,705		5.1	%		9,000		6.4	%
	5		1,250		0.4	%		500		0.4	%

Totals		$	346,759		100.0	%	$	140,703		100.0	%

		Page

PART I
Item 1.	Business	1
Item 1A.	Risk Factors	20
Item 1B.	Unresolved Staff Comments	36
Item 2.	Properties	36
Item 3.	Legal Proceedings	36
Item 4.	Reserved	36
PART II
Item 5.	Market for Registrant's Common Equity, Related Stockholder Matters and Issuer Purchases of Equity Securities	37
Item 6.	Selected Financial Data	42
Item 7.	Management's Discussion and Analysis of Financial Condition and Results of Operations	44
Item 7A.	Quantitative and Qualitative Disclosures About Market Risk	62
Item 8.	Financial Statements and Supplementary Data	64
Item 9.	Changes in and Disagreements with Accountants on Accounting and Financial Disclosure	118
Item 9A.	Controls and Procedures	118
Item 9B.	Other Information	118
PART III
Item 10.	Directors, Executive Officers and Corporate Governance	118
Item 11.	Executive Compensation	119
Item 12.	Security Ownership of Certain Beneficial Owners and Management and Related Stockholder Matters	119
Item 13.	Certain Relationships and Related Transactions, and Director Independence	119
Item 14.	Principal Accountant Fees and Services	119
PART IV
Item 15.	Exhibits and Financial Statement Schedules	120
Signatures		123

		(10.0)%			(5.0)%			0.0%			5.0%			10.0%

Corresponding net return to common stockholder			(22.2	)%		(13.2	)%		(4.2	)%		4.8	%		13.7	%

	Prior to Sale Below NAV			Following Sale Below NAV

*Reduction to NAV*
Total Shares Outstanding		1,000,000			1,040,000		4.0	%
NAV per share	$	10.00		$	9.98		(0.2	)%
*Dilution to Existing Stockholder*
Shares Held by Stockholder A		10,000			10,000	(1)	0.0	%
Percentage Held by Stockholder A		1.00	%		0.96	%	(3.8	)%
Total Interest of Stockholder A in NAV	$	100,000		$	99,808		(0.2	)%

		High		Low

Fiscal year 2010
	Fourth quarter	$	18.19	$	16.01
	Third quarter	$	16.90	$	14.78
	Second quarter	$	16.90	$	13.71
	First quarter	$	16.14	$	13.95
Fiscal year 2009
	Fourth quarter	$	16.35	$	13.29
	Third quarter	$	14.25	$	13.03
	Second quarter	$	14.74	$	9.66
	First quarter	$	10.43	$	9.07

Date Declared			Record Date	Payment Date	Amount(1)

Fiscal year 2011
	March 9, 2011		March 24, 2011	April 15, 2011	$	0.130
	March 9, 2011		April 21, 2011	May 16, 2011	$	0.130
	March 9, 2011		May 20, 2011	June 15, 2011	$	0.130
	December 9, 2010		February 22, 2011	March 15, 2011	$	0.125
	December 9, 2010		January 20, 2011	February 15, 2011	$	0.125
	December 9, 2010		January 6, 2011	January 14, 2011	$	0.125

		Total			$	0.765

Cost:

First lien debt	70.6	%	69.3	%
Equity	17.7	%	13.4	%
Second lien debt	6.7	%	10.7	%
Equity warrants	5.0	%	6.6	%

	100.0	%	100.0	%

Fair Value:

First lien debt	62.6	%	57.4	%
Equity	21.9	%	19.5	%
Equity warrants	9.0	%	13.5	%
Second lien debt	6.5	%	9.6	%

	100.0	%	100.0	%

Cost:

Southwest	50.5	%	50.1	%
West	29.3	%	28.6	%
Midwest	7.2	%	6.9	%
Southeast	7.0	%	9.0	%
Northeast	6.0	%	5.4	%

	100.0	%	100.0	%

Fair Value:

Southwest	51.8	%	51.1	%
West	28.4	%	28.4	%
Midwest	7.2	%	6.3	%
Southeast	6.4	%	8.4	%
Northeast	6.2	%	5.8	%

	100.0	%	100.0	%

	Total		2011		2012		2013		2014		2015		2016 and thereafter

	(dollars in thousands)
SBIC debentures	$	180,000	$	—	$	—	$	4,000	$	18,000	$	23,100	$	134,900
Interest due on SBIC debentures		66,147		9,313		9,429		9,403		9,097		8,011		20,894

Total	$	246,147	$	9,313	$	9,429	$	13,403	$	27,097	$	31,111	$	155,794


Reports of Independent Registered Public Accounting Firm		65
Consolidated Balance Sheets as of December 31, 2010 and 2009		67
Consolidated Statements of Operations for the Years Ended December 31, 2010, 2009, and 2008		68
Consolidated Statements of Changes in Net Assets for the Years Ended December 31, 2010, 2009, and 2008		69
Consolidated Statements of Cash Flows for the Years Ended December 31, 2010, 2009, and 2008		70
Consolidated Schedules of Investments as of December 31, 2010 and 2009		71
Notes to Consolidated Financial Statements		86

Type of Investment	December 31, 2009 Fair Value		MSC II Exchange Offer			Accretion of Unearned Income		Redemptions/ Repayments/ Exits(1)			New Investments(1)		Net Changes from Unrealized to Realized			Net Unrealized Appreciation (Depreciation)			December 31, 2010 Fair Value

Debt	$	84,309,980	$	56,143,458		$	1,434,415	$	(24,376,914	)	$	63,375,038	$	3,702,132		$	(694,039	)	$	183,894,070
Equity		30,377,672		9,066,290			—		1,647,363			17,372,359		(485,735	)		3,223,771			61,201,720
Equity warrants		11,197,571		5,864,324			—		(3,678,017	)		4,396,354		(327,983	)		7,628,714			25,080,963
Investment Manager		16,036,838		(13,715,958	)		—		—			—		—			(269,225	)		2,051,655

	$	141,922,061	$	57,358,114		$	1,434,415	$	(26,407,568	)	$	85,143,751	$	2,888,414		$	9,889,221		$	272,228,408

Type of Investment	December 31, 2009 Fair Value		SBIC Debentures Acquired in MSC II Exchange Offer		Repayments		New SBIC Debentures		Net Unrealized (Appreciation) Depreciation			December 31, 2010 Fair Value

SBIC Debentures at fair value	$	—	$	53,139,092	$	—	$	25,000,000	$	(7,581,117	)	$	70,557,975

			Fair Value Measurements

At December 31, 2010	Fair Value		Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
LMM portfolio investments	$	279,619,629	$	—	$	9,442,876	$	270,176,753
Private placement portfolio investments		67,139,790		—		67,139,790		—
Investment in affiliated Investment Manager		2,051,655		—		—		2,051,655

Total portfolio investments		348,811,074		—		76,582,666		272,228,408
Marketable securities and idle funds investments		68,752,858		—		68,752,858		—

Total investments	$	417,563,932	$	—	$	145,335,524	$	272,228,408

SBIC Debentures at fair value	$	70,557,975	$	—	$	—	$	70,557,975

			Fair Value Measurements

At December 31, 2009	Fair Value		Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
LMM portfolio investments	$	125,885,223	$	—	$	—	$	125,885,223
Private placement portfolio investments		14,817,933		—		14,817,933		—
Investment in affiliated Investment Manager		16,036,838		—		—		16,036,838

Total portfolio investments		156,739,994		—		14,817,933		141,922,061
Marketable securities and idle funds investments		3,252,954		—		3,252,954		—

Total investments	$	159,992,948	$	—	$	18,070,887	$	141,922,061

	As of December 31,

	2010			2009
SBIC debenture commitment fees	$	1,000,000		$	650,000
SBIC debenture leverage fees		2,095,075			1,610,075
Other		953,154			423,109

Subtotal		4,048,229			2,683,184
Accumulated amortization		(1,504,584	)		(1,071,676	)

Net deferred financing costs balance	$	2,543,645		$	1,611,508

Years Ended December 31,	Estimated Amortization

2011	$	538,410
2012	$	540,399
2013	$	469,593
2014	$	238,070
2015	$	174,283
2016 and thereafter	$	493,371

	Years Ended December 31,

	2010		Pro Forma 2009
	(Unaudited)
	(Dollars in millions except per share amounts)
Total investment income	$	36.5	$	26.7

Net investment income	$	19.3	$	12.6

Net increase in net assets resulting from operations attributable to common stock	$	38.7	$	11.4

Net investment income per share — basic and diluted	$	1.16	$	0.87

Net increase in net assets resulting from operations attributable to common stock per share — basic and diluted	$	2.38	$	0.80

	2010

	Qtr. 1		Qtr. 2		Qtr. 3		Qtr. 4
Total investment income	$	7,092,839	$	8,732,219	$	9,005,955	$	11,676,894
Net investment income	$	3,220,253	$	4,742,088	$	4,757,564	$	6,540,747
Net increase in net assets resulting from operations attributable to common stock	$	9,056,545	$	8,872,666	$	10,943,302	$	9,871,351
Net investment income per share-basic and diluted	$	0.22	$	0.31	$	0.28	$	0.34
Net increase in net assets resulting from operations attributable to common stock per share-basic and diluted	$	0.63	$	0.59	$	0.65	$	0.53

Plan Category	Number of Securities to be Issued Upon Exercise of Outstanding Options, Warrants and Rights		Weighted-Average Exercise Price of Outstanding Options, Warrants and Rights		Number of Securities Remaining Available for Future Issuance Under Equity Compensation Plans (Excluding Securities Reflected in Column(a))

	(a)		(b)		(c)
Equity compensation plans approved by security holders		—	$	—		1,669,573	(1)
Equity compensation plans not approved by security holders		—		—		—

Total		—	$	—		1,669,573


		Report of Independent Registered Public Accounting Firm
		Schedule of Investments in and Advances to Affiliates for the Year Ended December 31, 2010

Exhibit Number			Description

	31.1		Rule 13a - 14(a)/15d - 14(a) certification of Chief Executive Officer
	31.2		Rule 13a - 14(a)/15d - 14(a) certification of Chief Financial Officer
	32.1		Section 1350 certification of Chief Executive Officer
	32.2		Section 1350 certification of Chief Financial Officer


	MAIN STREET CAPITAL CORPORATION
	By:	/s/ VINCENT D. FOSTER Vincent D. Foster Chairman and Chief Executive Officer
Date: March 11, 2011

Signature	Title	Date


/s/ VINCENT D. FOSTER Vincent D. Foster	Chairman and Chief Executive Officer (principal executive officer)	March 11, 2011
/s/ TODD A. REPPERT Todd A. Reppert	President, Chief Financial Officer and Director (principal financial officer)	March 11, 2011
/s/ MICHAEL S. GALVAN Michael S. Galvan	Vice President, Chief Accounting Officer (principal accounting officer)	March 11, 2011
/s/ RODGER A. STOUT Rodger A. Stout	Senior Vice President-Finance & Administration, Chief Compliance Officer and Treasurer	March 11, 2011
/s/ JOSEPH E. CANON Joseph E. Canon	Director	March 11, 2011
/s/ MICHAEL APPLING JR. Michael Appling Jr.	Director	March 11, 2011
/s/ WILLIAM D. GUTERMUTH William D. Gutermuth	Director	March 11, 2011
/s/ ARTHUR L. FRENCH Arthur L. French	Director	March 11, 2011

Exhibit Number			Description

	21.1		List of Subsidiaries
	23		Consent of Grant Thornton LLP, independent registered public accounting firm
	31.1		Rule 13a - 14(a)/15d - 14(a) certification of Chief Executive Officer
	31.2		Rule 13a - 14(a)/15d - 14(a) certification of Chief Financial Officer
	32.1		Section 1350 certification of Chief Executive Officer
	32.2		Section 1350 certification of Chief Financial Officer