Jill E. York - 17 Feb 2026 Form 4 Insider Report for OLD SECOND BANCORP INC (OSBC)

Reporting relationship: Director
Issuer ticker: OSBC
Reported as of: 17 Feb 2026
Net transaction value: -$63,294
SEC form: 4
Accepted by SEC: 24 Feb 2026, 19:39:09 UTC
Prior SEC filing: 21 Feb 2025
Next SEC filing: 21 Oct 2026
Source filing: View source filing
Reporting owner signature: /s/ Shirley Cantrell, Attorney-in-Fact

Filing notes and source

Key filing fact

Jill E. York filed Form 4 for OLD SECOND BANCORP INC (OSBC) on 24 Feb 2026.

Key facts

This page summarizes Jill E. York's Form 4 filing for OLD SECOND BANCORP INC (OSBC).
2 reported transactions and 0 derivative rows are listed below.
Accepted by SEC: 24 Feb 2026, 19:39.

Change

Previous filing in this sequence was filed on 21 Feb 2025.
Current net transaction value: -$63,294.

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 0001244438 Primary reporting owner

YORK JILL E

Relationship: Director
Address: C/O MB FINANCIAL INC, 6111 NORTH RIVER ROAD, ROSEMONT
Signature: /s/ Shirley Cantrell, Attorney-in-Fact
Signature date: 24 Feb 2026

Reported non-derivative transactions

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

OSBC transaction

Restricted Stock Units

Award

Transaction value: $0
Shares: +3,121
Change %: +30%
Price: $0.000000
Shares after: 13,672
Date: 17 Feb 2026
Ownership: Direct
Footnotes: F1

OSBC transaction

Restricted Stock Units

Tax liability

Transaction value: -$63,294
Shares: -3,077
Change %: -23%
Price: $20.57
Shares after: 10,595
Date: 21 Feb 2026
Ownership: Direct
Footnotes: F2

OSBC holding

Old Second Bancorp, Inc. Common Stock

No transaction description listed

Transaction value
Shares
Change %
Price
Shares after: 3,077
Date: 17 Feb 2026
Ownership: Direct
Footnotes: F3

OSBC holding

Old Second Bancorp, Inc. Common Stock

No transaction description listed

Transaction value
Shares
Change %
Price
Shares after: 21,626
Date: 17 Feb 2026
Ownership: Held in Trust with spouse

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

Additional SEC filing notes

Filing notes and footnotes

Explanation of responses 3 footnotes

Footnote F1

These shares represent restricted stock units granted pursuant to the Old Second Bancorp, Inc. Long Term Incentive Plan. These shares have a three-year cliff vesting.

Footnote F2

Represents shares vested upon the third anniversary of the date of grant previously reported and are now issued and added to the reporting person's common stock holdings outright.

Footnote F3

These shares are held in Ms. York's name outright.