Main Street Capital Corporation (MSCC) is a principal investment firm. MSCC is primarily focused on providing customized debt and equity financing to lower middle market (LMM) companies and debt capital to middle market (Middle Market) companies. The Company's portfolio investments are made to support management buyouts, recapitalizations, growth financings, refinancings and acquisitions of companies that operate in various industry sectors. The Company invests primarily in secured debt investments, equity investments, warrants and other securities of LMM companies based in the United States and in secured debt investments of Middle Market companies generally headquartered in the United States. The Company's investment portfolio includes its investments in LMM portfolio companies, investments in Middle Market portfolio companies, Private Loan portfolio investments, Other Portfolio investments, and the investment in MSC Adviser I, LLC (the External Investment Manager).