Old Second Bancorp is the holding company for Old Second National Bank, a community bank headquartered in Aurora, Illinois, roughly 40 miles west of Chicago. The bank operates primarily across seven Illinois counties in the western and southern Chicago suburbs, serving businesses, real estate owners, and consumers through a 55-branch network. Old Second's core business is traditional commercial and community banking — taking deposits and making loans — with a loan book anchored by commercial real estate (~37% of loans) and commercial and industrial lending (~16%). The July 2025 acquisition of Evergreen Bank Group added a nationwide powersports consumer lending platform (motorcycles, ATVs, snowmobiles, personal watercraft originated through a dealer network), now representing ~13% of loans, alongside manufactured home lending and collector car financing. Old Second earns primarily through net interest income, with net interest margin running above 5% on a tax-equivalent basis — unusually high for a community bank — driven by a low-cost granular deposit base and the high-yield powersports loan book, which carries average coupons near 9%. Fee income comes from wealth management (~$2.29B in assets under administration or management), mortgage banking, and powersports servicing. Old Second has grown through M&A, including a five-branch acquisition from First Merchants in late 2024, and organically through specialty verticals including sponsor finance, healthcare lending, and equipment leasing.