O2 Sponsor Finance Hires Aaron Markos as Senior Vice President

CHICAGO, IL / ACCESS Newswire / September 2, 2026 / O2 Sponsor Finance, a division of Old Second National Bank, today announced that it has recently hired Aaron Markos as Senior Vice President.

"We are excited to announce that Aaron Markos has joined as Senior Vice President of O2 Sponsor Finance. Aaron is responsible for sourcing, structuring, and underwriting new lending opportunities while partnering closely with equity sponsors and management teams. Aaron will play an important role in supporting our continued growth strategy, deepening existing sponsor relationships, and helping expand our presence across the lower middle market sponsor finance landscape. We are excited about the expertise, leadership and industry perspective Aaron brings to the team and look forward to his contributions in 2026 and beyond." Said O2 Sponsor Finance President Joe Gaffigan.

Aaron brings substantial experience to his new role, having built a strong track record across sponsor finance, direct lending, and leveraged finance. Prior to joining O2, Aaron held positions at Deerpath Capital Management, L.P., First Midwest Bank Structured Finance Group (now Old National Bank), and Fifth Third Bank Structured Finance Group. He also gained valuable experience earlier in his career at both LaSalle National Bank and American National Bank. Throughout his career, Aaron has worked closely with private equity firms, supporting acquisition financings, recapitalizations, growth initiatives, and portfolio company investments across a variety of industries.

Aaron earned an MBA in Finance from the University of Notre Dame and a BSBA in Finance from Roosevelt University.

About O2 Sponsor Finance: O2 Sponsor Finance is a national provider of cash flow-based loans to lower middle market businesses with typically $10 to $100 million in revenue and between $2 million and $10 million in EBITDA. O2 Sponsor Finance focuses on supporting private equity sponsors, independent sponsors and family offices in their acquisition or recapitalization of lower middle market companies. www.O2sponsorfinance.com.

About Old Second Bancorp, Inc.: Old Second Bancorp, Inc., headquartered in Aurora, Illinois, is the bank holding company for Old Second National Bank, which celebrated 150 years of operation in 2021. Old Second's common stock trades on The NASDAQ Stock Market under the symbol "OSBC". More information about Old Second is available by visiting the "Investor Relations" section of its website: www.oldsecond.com.

As of June 30, 2026, Old Second has approximately $6.9 billion in assets, $5.4 billion in deposits and $5.2 billion in loans.

Old Second National Bank, Member FDIC.

Contact:

Bradley S. Adams EVP, Chief Operating Officer and Chief Financial Officer (630) 906-5484

SOURCE: Old Second Bancorp Inc.