Bain Capital Specialty Finance Inc | 6 followers on LinkedIn. Bain Capital Specialty Finance, Inc. is a managed specialty finance company focused on lending to middle market companies. The fund seeks to invest in senior investments with a first or second lien on collateral, senior first lien, stretch senior, senior second lien, unitranche, mezzanine debt, junior securities, other junior investments, and secondary purchases of assets or portfolios that primarily consist of middle-market corporate debt. The Company's investment portfolio also includes corporate bonds, investment vehicles, equity interest, and preferred equity.