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MAIN ST CAPITAL CORPORATION ● ● ● Third Quarter 2021 Net Investment Income of $ 0.71 Per Share Third Quarter 2021 Distributable Net Investment Income¹ of $ 0.76 Per Share Net Asset Value of $ 24.27 Per Share HOUSTON , November 4 , 2021 – Main Street Capital Corporation ( NYSE : MAIN ) ( “ Main Street " ) is pleased to announce its financial results for the third quarter of 2021 . Third Quarter 2021 Highlights ● ● NEWS RELEASE ● Contacts : Main Street Capital Corporation Dwayne L. Hyzak , CEO , dhyzak@mainstcapital.com Jesse E. Morris , CFO and COO , jmorris@mainstcapital.com 713-350-6000 Dennard Lascar Investor Relations Ken Dennard / ken@dennardlascar.com Zach Vaughan / zvaughan@dennardlascar.com 713-529-6600 MAIN STREET ANNOUNCES THIRD QUARTER 2021 RESULTS Net investment income of $ 49.3 million ( or $ 0.71 per share ) Distributable net investment income ( ¹ ) of $ 52.2 million ( or $ 0.76 per share ) Total investment income of $ 76.8 million An industry leading position in cost efficiency , with a ratio of total non - interest operating expenses as a percentage of quarterly average total assets ( “ Operating Expenses to Assets Ratio " ) of 1.6 % on an annualized basis for the quarter and 1.5 % for the trailing twelve month ( " TTM " ) period ended September 30 , 2021 Net increase in net assets resulting from operations of $ 84.0 million ( or $ 1.22 per share ) Return on equity ( 2 ) of 20.4 % on an annualized basis for the quarter and 20.3 % for the TTM period ended September 30 , 2021 Net asset value of $ 24.27 per share at September 30 , 2021 , representing an increase of $ 0.85 per share , or 3.6 % , compared to $ 23.42 per share at June 30 , 2021 , and $ 1.92 per share , or 8.6 % , compared to $ 22.35 per share at December 31 , 2020 Declared monthly dividends totaling $ 0.63 per share for the fourth quarter of 2021 , or $ 0.21 per share for each of October , November and December 2021 , representing a 2.4 % increase from the monthly dividends paid for the third quarter of 2021 and the fourth quarter of 2020 Completed $ 159.2 million in total lower middle market ( “ LMM " ) portfolio investments , including investments totaling $ 73.3 million in four new LMM portfolio companies , which after aggregate repayments of debt principal and return of invested equity capital from several LMM portfolio investments resulted in a net increase of $ 135.2 million in total LMM portfolio investments Completed $ 117.5 million in total private loan portfolio investments , which after aggregate repayments of debt principal and return of invested equity capital from several private loan portfolio investments resulted in a net decrease of $ 20.3 million in total private loan portfolio investments Net decrease of $ 17.4 million in middle market portfolio investments Fully exited portfolio company investments in NRI Clinical Research , LLC , realizing a gain of $ 8.8 million and resulting in annual internal rate of returns and times money invested returns of 38.5 % and 15.2 times on its equity investments and 20.2 % and 2.6 times on a cumulative basis including all debt and equity investments in the company , respectively