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.

UBM is a leading provider of "marketing mail" commingle services, specializing in optimizing postage, transportation and delivery performance for large-scale mailers. Through a nationwide logistics network and technology-driven processes, UBM helps clients improve speed-to-market, visibility and cost efficiency across their marketing mail programs.

Mystic specializes in marketing mail consolidation and logistics solutions designed to support precise, date-driven in-home delivery performance. Through disciplined transportation planning, mail flow optimization and performance tracking, Mystic helps clients align marketing campaigns with targeted in-home delivery windows to drive consistent and measurable results.

Main Street originally partnered with Mystic's executive management team to facilitate a majority recapitalization in August 2014. Main Street's initial investment consisted of a $10.0 million first lien, senior secured term loan and a $2.7 million majority equity investment. After Main Street's initial investment, Mystic experienced significant growth as the company expanded its customer base and strengthened its postal and commercial partnerships.

Main Street realized a gain of $23.8 million on the exit of its equity investment in Mystic and also received total dividends of $22.1 million over the life of its equity investment. As a result, on a cumulative basis since Main Street's initial investment in August 2014 and taking the realized gain and dividends into consideration, Main Street realized an annual internal rate of return ("IRR") of 32.9% and a 17.9 times money invested ("TMI") return on its equity investment in Mystic. On a cumulative basis including both Main Street's debt and equity investments, Main Street realized an IRR of 22.9% and a 5.1 TMI return.

ABOUT MAIN STREET CAPITAL CORPORATION
Main Street (www.mainstcapital.com) is a principal investment firm that primarily provides customized long-term debt and equity capital solutions to lower middle market companies and debt capital to private companies owned by or in the process of being acquired by a private equity fund. Main Street's portfolio investments are typically made to support management buyouts, recapitalizations, growth financings, refinancings and acquisitions of companies that operate in diverse industry sectors. Main Street seeks to partner with entrepreneurs, business owners and management teams and generally provides customized "one-stop" debt and equity financing solutions within its lower middle market investment strategy. Main Street seeks to partner with private equity fund sponsors and primarily invests in secured debt investments in its private loan investment strategy. Main Street's lower middle market portfolio companies generally have annual revenues between $10 million and $150 million. Main Street's private loan portfolio companies generally have annual revenues between $25 million and $500 million.

Main Street, through its wholly-owned portfolio company MSC Adviser I, LLC ("MSC Adviser"), also maintains an asset management business through which it manages investments for external parties. MSC Adviser is registered as an investment adviser under the Investment Advisers Act of 1940, as amended.

Contacts:
Main Street Capital Corporation
Dwayne L. Hyzak, CEO, [email protected]
Ryan R. Nelson, CFO, [email protected]           
713-350-6000 

Dennard Lascar Investor Relations
Ken Dennard | [email protected]  
Zach Vaughan | [email protected]  
713-529-6600

SOURCE Main Street Capital Corporation