James Eccher - 31 Dec 2025 Form 4 Insider Report for OLD SECOND BANCORP INC (OSBC)

Role: CHAIRMAN AND CEO, Director
Signature: /s/ Shirley Cantrell, Attorney-in-Fact
Issuer symbol: OSBC
Transactions as of: 31 Dec 2025
Net transactions value: $0
Form type: 4
Filing time: 05 Jan 2026, 18:24:24 UTC
Previous filing: 01 Oct 2025
Next filing: 24 Feb 2026
SEC: View on sec.gov

Reporting Owners (1)

Name	Relationship	Address	Signature	Signature date	CIK
Eccher James	CHAIRMAN AND CEO, Director	37 S. RIVER ST., AURORA	/s/ Shirley Cantrell, Attorney-in-Fact	05 Jan 2026	0001314109

Transactions Table

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Ownership	Footnotes
transaction	OSBC	Old Second Bancorp, Inc. Common Stock	Other	$0	+125	+0.38%	$0.000000	33,018	31 Dec 2025	By 401-K	F1
transaction	OSBC	Old Second Bancorp, Inc. Common Stock	Other	$0	+24	+0.38%	$0.000000	6,335	31 Dec 2025	By Profit Sharing	F2
holding	OSBC	Old Second Bancorp, Inc. Common Stock						329,896	31 Dec 2025	Direct	F3
holding	OSBC	Restricted Stock Units						184,318	31 Dec 2025	Direct

* An asterisk sign (*) next to the price indicates that the price is likely invalid.

Explanation of Responses:

Id	Content
F1	Of this total, 125 shares were allocated during the fourth quarter pursuant to the Old Second Bancorp, Inc. Employee Salary and Savings Plan. Information herein was provided by the Plan Trustee as of 12-31-25.
F2	Of this total, 24 shares were allocated during the fourth quarter pursuant to the Old Second Bancorp, Inc. Employee Profit Sharing Plan & Trust. Information herein was provided by the Plan Trustee as of 12-31-25.
F3	Included in this total are 148 shares held jointly with spouse and 329,748 shares held in a brokerage account.