Exhibit 99.1 NEWS RELEASE Contacts: Main Street Capital Corporation Dwayne L. Hyzak, CEO, dhyzak@mainstcapital.com Ryan R. Nelson, CFO, rnelson@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 Fourth Quarter 2025 Private Loan Portfolio Activity HOUSTON – January 8, 2026 – Main Street Capital Corporation (NYSE: MAIN) ("Main Street") is pleased to announce the following recent activ ...