OLD SECOND BANCORP INC — Director's Dealing 2025

Jul 21, 2025

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: OLD SECOND BANCORP INC (OSBC)
CIK: 0000357173
Period of Report: 2025-07-18

Reporting Person: Campbell Darin Patrick (N/A)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2025-07-18	Old second Bancorp Inc., Common Stock	A	57565	—	Acquired	57565	Indirect

Holdings (Non-Derivative)

Security	Shares	Ownership
Old Second Bancorp, Inc. Common Stock	309680	Direct

Footnotes

F1: These shares were issuable pursuant to the merger of Bancorp Financial, Inc. with and into Old Second Bancorp, Inc., which became effective on July 1, 2025. The reporting person held 22,300 shares of Bancorp Financial, Inc., which pursuant to the merger agreement was converted into 57,565 shares of Old Second Bancorp, Inc. common stock. These shares are held in a custodial account in an IRA on behalf of the reporting person. The exchange of shares occurred on July 19, 2025.

F2: These securities are issuable pursuant to the merger of Bancorp Financial, Inc. with and into Old Second Bancorp, Inc., which became effective on July 1, 2025. The reporting person held 119,966 shares of Bancorp Financial, Inc., which pursuant to the merger agreement, will be converted into 309,680 shares of Old Second Bancorp, Inc. common stock. The exchange of shares has not yet occurred, but the right to receive the shares is fixed and irrevocable under the merger agreement. The exchange of shares occurred on July 18, 2025.