Donald Pilmer - 30 Sep 2026 Form 4 Insider Report for OLD SECOND BANCORP INC (OSBC)

Reporting relationship: EVP
Issuer ticker: OSBC
Reported as of: 30 Sep 2026
Net transaction value: $0
SEC form: 4
Accepted by SEC: 01 Oct 2026, 14:17:59 UTC
Prior SEC filing: 02 Jul 2026
Source filing: View source filing
Reporting owner signature: /s/ Shirley Cantrell, Attorney-in-Fact

Filing notes and source

Key filing fact

Donald Pilmer filed Form 4 for OLD SECOND BANCORP INC (OSBC) on 01 Oct 2026.

Key facts

This page summarizes Donald Pilmer's Form 4 filing for OLD SECOND BANCORP INC (OSBC).
1 reported transaction and 0 derivative rows are listed below.
Accepted by SEC: 01 Oct 2026, 14:17.

Change

Previous filing in this sequence was filed on 02 Jul 2026.
Current net transaction value: $0.

Research use

This tells you what this filing adds before you inspect full transaction and derivative tables.
You can trace every row back to the original SEC filing document.

Evidence

Filed on Form 4

Ownership activity is grounded in SEC Form 4 disclosures.

View source filing

Reporting Owners (1)

CIK 0001673321 Primary reporting owner

Pilmer Donald

Relationship: EVP
Address: 37 S. RIVER ST., AURORA
Signature: /s/ Shirley Cantrell, Attorney-in-Fact
Signature date: 01 Oct 2026

Reported non-derivative transactions

Shares, units, or other non-derivative securities reported in this filing.

OSBC transaction

Old Second Bancorp, Inc. Common Stock

Other

Transaction value
Shares: +11
Change %: +0.27%
Price: $0.000000^*
Shares after: 4,048
Date: 30 Sep 2026
Ownership: By 401-K Plan
Footnotes: F1

OSBC holding

Old Second Bancorp, Inc. Common Stock

No transaction description listed

Transaction value
Shares
Change %
Price
Shares after: 184
Date: 30 Sep 2026
Ownership: By Profit Sharing Plan

OSBC holding

Old Second Bancorp, Inc. Common Stock

No transaction description listed

Transaction value
Shares
Change %
Price
Shares after: 1,450
Date: 30 Sep 2026
Ownership: Spouse's IRA
Footnotes: F2

OSBC holding

Old Second Bancorp, Inc. Common Stock

No transaction description listed

Transaction value
Shares
Change %
Price
Shares after: 48,054
Date: 30 Sep 2026
Ownership: Direct

OSBC holding

Restricted Stock Units

No transaction description listed

Transaction value
Shares
Change %
Price
Shares after: 39,498
Date: 30 Sep 2026
Ownership: Direct

^* marks a reported price that did not pass the local price check.

Additional SEC filing notes

Filing notes and footnotes

Explanation of responses 2 footnotes

Footnote F1

These shares were allocated during the third quarter pursuant to the Old Second Bancorp, Inc. Employee Savings Plan & Trust. Information herein was provided by the Plan Trustee as of 9-30-26.

Footnote F2

These shares are held in spouse's IRA for which Mr. Pilmer is listed as a beneficiary.