Main Street Announces Investments in New Portfolio Company and Exit of Investments in an Existing Portfolio Company

Provides $50.8 Million of Financing to UBM ParentCo, LLC

Generates $23.8 Million Realized Gain from the Exit of Equity Investment in Mystic Logistics Holdings, LLC

HOUSTON, Jan. 6, 2026 /PRNewswire/ — Main Street Capital Corporation (NYSE: MAIN) („Main Street“) is pleased to announce that it recently completed a new portfolio investment totaling $50.8 million in UBM ParentCo, LLC, doing business as United Business Mail („UBM“ or the „Company“), to facilitate UBM’s merger with Mystic Logistics Holdings, LLC („Mystic“), an existing Main Street portfolio company. Main Street partnered with both the Company’s and Mystic’s existing owners and management teams to facilitate the transaction, with Main Street’s new investment including a combination of first lien, senior secured term debt and direct minority equity. As a result of the transaction, Main Street fully exited its debt and equity investments in Mystic and is now a lender and minority equity owner in UBM.