Main Street Capital : 1st Quarter 2024 Investor Presentation

Investor Presentation

First Quarter - 2024

Main Street Capital Corporation

NYSE: MAIN

mainstcapital.com

Disclaimers

Main Street Capital Corporation (MAIN) cautions that statements in this presentation that are forward-looking, and provide other than historical information, involve risks and uncertainties that may impact our future results of operations. The forward-looking statements in this presentation are based on current conditions as of May 10, 2024, and include, but are not limited to, statements regarding our goals, beliefs, strategies, future operating results and cash flows, operating expenses, investment originations and performance, available capital, payment and the tax attributes of future dividends and shareholder returns. Although our management believes that the expectations reflected in any forward-looking statements are reasonable, we can give no assurance that those expectations will prove to have been correct. Those statements are made based on various underlying assumptions and are subject to numerous uncertainties and risks, including, without limitation: our continued effectiveness in raising, investing and managing capital; adverse changes in the economy generally or in the industries in which our portfolio companies operate; the impacts of macroeconomic factors on MAIN and its portfolio companies' business and operations, liquidity and access to capital, and on the U.S. and global economies, including impacts related to pandemics and other public health crises, risk of recession, inflation, supply chain constraints or disruptions and changes in market index interest rates; changes in laws and regulations or business, political and/or regulatory conditions that may adversely impact our operations or the operations of our portfolio companies; the operating and financial performance of our portfolio companies and their access to capital; retention of key investment personnel; competitive factors; and such other factors described under the captions "Cautionary Statement Concerning Forward-Looking Statements," "Management's Discussion and Analysis of Financial Condition and Results of Operations" and "Risk Factors" included in our filings with the Securities and Exchange Commission (the SEC)(www.sec.gov), including our most recent annual report on Form 10-K and subsequently filed quarterly reports on Form 10-Q. We undertake no obligation to update the information contained herein to reflect subsequently occurring events or circumstances, except as required by applicable securities laws and regulations.

Main Street Capital Corporation

MAIN has filed a registration statement (which includes a prospectus) with the SEC for any offering to which this communication may relate and may file one or more supplements to the prospectus in the future.

MAIN is classified as a non-diversified investment company within the meaning of the 1940 Act, which means that it is not limited by the 1940 Act with respect to the proportion of its assets that it may invest in securities of a single issuer. Before you invest in any of MAIN's securities, you should read the registration statement, the prospectus and the applicable prospectus supplement(s) in order to fully understand all of the implications and risks of an offering of MAIN's securities. You should also read other documents MAIN has filed with the SEC for more complete information about MAIN and its securities offerings. You may access these documents for free by visiting EDGAR on the SEC website at www.sec.gov. Alternatively, MAIN will arrange to send you any applicable prospectus and prospectus supplement if you request such materials by calling us at [phone]. These materials are also made available, free of charge, on our website at www.mainstcapital.com. Information contained on our website is not incorporated by reference into this communication.

The summary descriptions and other information included herein are intended only for informational purposes and convenient reference. The information contained herein is not intended to provide, and should not be relied upon for, accounting, legal or tax advice or investment recommendations. Before making an investment decision with respect to MAIN, investors are advised consult with their tax, financial, investment and legal advisors.

NYSE: MAIN

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Main Street Capital Corporation

Corporate Overview and Investment Strategy

1st Quarter - 2024

Main Street Capital Corporation

NYSE: MAIN

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MAIN is a Principal Investor in Private Debt and Equity

Focus on unique Lower Middle Market debt and equity investment strategy, Asset Management Business and internally managed operating structure differentiates MAIN from other investment firms

Internally-managed Business Development Company (BDC)

• IPO in 2007
• Over $7.4 billion in capital under management(1)
• • Over $5.8 billion internally at MAIN(1)
  • Over $1.6 billion as the investment adviser to external parties(1)

Primarily invests in the under-served Lower Middle Market (LMM)

• Targets companies with revenue between $10 million - $150 million; EBITDA between $3 million - $20 million
• Provides single source solutions, including a combination of first lien, senior secured debt and equity financing

Proprietary debt investments in privately held companies typically owned by private equity sponsors (Private Loans)

• Originated directly by MAIN or through strategic relationships with other investment funds
• First lien, senior secured debt investments
• Companies consistent with size of the companies in MAIN's LMM and Middle Market investment strategies

Debt investments in Middle Market companies

• First lien, senior secured and/or rated debt investments
• Larger companies than LMM investment strategy

Attractive asset management advisory business Significant management ownership / investment in MAIN Headquartered in Houston, Texas

1. Capital under management includes undrawn portion of debt capital as of March 31, 2024

Main Street Capital Corporation

NYSE: MAIN

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MAIN is a Principal Investor in Private Debt and Equity

MAIN's unique investment strategy, efficient operating structure and conservative capitalization are designed to provide sustainable, long-term growth in recurring monthly dividends, meaningful supplemental quarterly dividends and long-term capital appreciation to our shareholders

Long-term focus on delivering our shareholders sustainable growth in net asset value and recurring dividends per share

Consistent cash dividend yield - dividends paid monthly

• MAIN has never decreased its monthly dividend rate
• 123% increase in monthly dividends from $0.33 per share paid in Q4 2007(2) to declared dividends of $0.735 per share for Q3 2024
• Supplemental dividends, paid or declared, in addition to monthly dividends, of $1.15 per share during the last twelve months(1)

Owns two Small Business Investment Company (SBIC) Funds

• Main Street Mezzanine Fund (2002 vintage) and Main Street Capital III (2016 vintage)
• Provides access to 10-year, low cost, fixed rate U.S. government- backed leverage

Strong capitalization and liquidity position - stable, long-term debt and significant available liquidity to take advantage of opportunities

1. • Favorable opportunities in capital markets through issuer investment grade ratings of BBB-/Stable from Fitch Ratings and BBB-/Stable from Standard & Poor's Global Ratings
   • Total SBIC debentures regulatory financing capacity of $350 million, the maximum amount permitted under current U.S. Small Business Administration (SBA) regulations
2. Includes dividends paid or declared as of May 10, 2024
3. MAIN's Initial Public Offering, or IPO, occurred in October 2007

Main Street Capital Corporation

NYSE: MAIN

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MAIN is a Principal Investor in Private Debt and Equity

Focus on LMM equity investments and efficient operating structure differentiates MAIN and provides opportunity for significant total returns for our shareholders

Equity investments in LMM portfolio provide the opportunity to grow net asset value (NAV) per share and generate recurring dividend income and periodic realized gains to support MAIN's dividend growth

• NAV growth of $16.69 per share (or 130%) since 2007
• Cumulative net realized gains from LMM portfolio investments of $75.6 million since MAIN's initial public offering(2)
• Approximately $6.00 per share in cumulative, pre-tax net unrealized appreciation on LMM portfolio as of March 31, 2024
• Realized gains provide opportunities for additional returns in excess of net investment income

Internally managed operating structure provides significant operating leverage

• Favorable ratio of total expenses, excluding interest expense, to average total assets of approximately 1.3%(1)
• Greater portion of gross portfolio returns are delivered to our shareholders
• Attractive and growing Asset Management Business benefits MAIN's shareholders
• Significant positive impact to Net Investment Income (NII)
• Alignment of interests between MAIN management and our shareholders

1. Based upon the trailing twelve-month period ended March 31, 2024
2. MAIN's Initial Public Offering, or IPO, occurred in October 2007

Main Street Capital Corporation

NYSE: MAIN

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MAIN Strategy Produces Differentiated Returns

Enhanced Value Proposition - ThreeWays to Win are Better Than One

1. Sustain and Grow Dividends

• Efficient operating structure provides operating leverage to grow Distributable Net Investment Income (DNII)(1), and dividends paid, as investment portfolio and total investment income grow
• 123% increase in monthly dividends from $0.33 per share paid in Q4 2007(2) to declared dividends of $0.735 per share for Q3 2024
• Never decreased regular monthly dividends (including through 2008/2009 recession and 2020/2021 COVID-19 pandemic)
• Paid or declared $41.59(3) per share in total dividends since IPO(2) at $15.00 per share ($35.55 per share in regular dividends and $6.04 per share in supplemental dividends)(3)
• Multi-facetedinvestment strategy supports growth of dividends over various cycles and markets

2. Meaningfully Grow Net Asset Value (NAV) Per Share

• $12.85 at December 31, 2007(2) to $29.54 at March 31, 2024 - 130% growth; CAGR of 5.3%
• Represents incremental economic return to investors beyond dividends
• MAIN's debt-focused peers (which comprises most BDCs) have not been able to generate NAV per share growth through the cycles
• Unrealized appreciation is a good proxy for future dividend growth without the need for additional capital through growing portfolio dividend income and periodic harvesting of realized gains from equity investments
• Ability to grow NAV per share provides opportunity for MAIN share price appreciation and additional shareholder returns

3. Supplement Growth in DNII(1) with Periodic Realized Gains

1. • LMM equity component of investment strategy provides opportunity for meaningful realized gains (analogous to PIK income on debt investments from cash flow perspective, but more tax efficient and without cap on upside)
   • Realized gains validate the quality of MAIN's unrealized appreciation on its LMM equity investments
   • Realized gains can be retained for future reinvestment due to MAIN's unique tax structure or paid to shareholders as dividends
2. See reconciliation of DNII per share to Net Investment Income per share on page 38 and Non-GAAP Information disclosures on page 48 of this presentation
3. MAIN's Initial Public Offering, or IPO, occurred in October 2007
4. Includes dividends paid or declared as of May 10, 2024

Main Street Capital Corporation

NYSE: MAIN

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Historical Monthly Dividends, NAV and DNII(1) Per Share

MAIN's unique focus on LMM equity investments provides the opportunity for significant NAV per share growth

MAIN's efficient operating structure provides significant operating leverage, greater dividends and greater overall returns for our shareholders

1. • In addition to the monthly dividends above, $6.04 per share of supplemental dividends have been paid or declared since 2007 IPO(2)
   • Annual return on equity averaging 14.0% from 2010 through the first quarter of 2024
2. See reconciliation of DNII per share to Net Investment Income per share on page 38 and Non-GAAP Information disclosures on page 48 of this presentation
3. Includes dividends paid or declared as of May 10, 2024

Main Street Capital Corporation

NYSE: MAIN

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LMM Investment Strategy

LMM investment strategy differentiates MAIN from its competitors and provides attractive risk- adjusted returns

MAIN's permanent capital structure as a publicly traded investment firm allows MAIN to maintain a long-term to permanent expected holding period for its LMM investments, providing significant benefits to both MAIN and our LMM portfolio companies

Main Street Capital Corporation

Investment Objectives

• High cash yield from secured debt investments (12.5% weighted- average cash coupon as of March 31, 2024); plus
• Dividend income, fair value appreciation and periodic capital gains from equity investments

Investments are structured for (i) protection of capital, (ii) high recurring income and (iii) meaningful capital gain opportunity

Focus on self-sponsored, "one stop" financing opportunities

• Partner with business owners, management teams and entrepreneurs
• Provide highly customized financing solutions
• Recapitalization, buyout, growth and acquisition capital
• Extensive network of grass roots referral sources
• Strong and growing "Main Street" brand recognition / reputation

Investments have low correlation to the broader debt and equity markets and attractive risk-adjusted returns

Unique LMM strategy, combined with MAIN's perpetual capital structure and goal to be long-term partners, results in a highly diversified and high-quality investment portfolio

NYSE: MAIN

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LMM Investment Opportunity

MAIN targets LMM investments in established, profitable companies

Characteristics of LMM provide beneficial risk- reward investment opportunities

Large and critical portion of U.S. economy

• 195,000+ domestic LMM businesses(1)

LMM is under-served from a capital perspective and less competitive

Inefficient asset class generates pricing inefficiencies

• Typical entry enterprise values between 4.5X - 6.5X EBITDA
• Typical entry leverage multiples between 2.0X - 4.0X EBITDA to MAIN debt investment

Partner relationship with the management teams of our portfolio companies vs a "commoditized vendor of capital"

1. Source: U.S. Census 2017 - U.S. Data Table by Enterprise Receipt Size; 2017 County Business Patterns and 2017 Economic Census; includes Number of Firms with Enterprise Receipt Size between $10,000,000 and $99,999,999

Main Street Capital Corporation

NYSE: MAIN

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