Donald Pilmer - 17 Feb 2026 Form 4 Insider Report for OLD SECOND BANCORP INC (OSBC)

Role
EVP
Signature
/s/ Shirley Cantrell, Attorney-in-Fact
Issuer symbol
OSBC
Transactions as of
17 Feb 2026
Net transactions value
-$37,396
Form type
4
Filing time
24 Feb 2026, 18:52:43 UTC
Previous filing
05 Jan 2026
Next filing
04 Mar 2026
SEC
View on sec.gov

Reporting Owners (1)

Name Relationship Address Signature Signature date CIK
Pilmer Donald EVP 37 S. RIVER ST., AURORA /s/ Shirley Cantrell, Attorney-in-Fact 24 Feb 2026 0001673321

Transactions Table

Type Sym Class Transaction Value $ Shares Change % * Price $ Shares After Date Ownership Footnotes
transaction OSBC Restricted Stock Units Award $0 +11,292 +29% $0.000000 50,010 17 Feb 2026 Direct F1
transaction OSBC Restricted Stock Units Tax liability $37,396 -1,818 -3.9% $20.57 44,754 21 Feb 2026 Direct F2
holding OSBC Old Second Bancorp, Inc. Common Stock 3,438 17 Feb 2026 Direct F3
holding OSBC Old Second Bancorp, Inc. Common Stock 63,135 17 Feb 2026 Direct
holding OSBC Old Second Bancorp, Inc. Common Stock 4,010 17 Feb 2026 By 401-K Plan
holding OSBC Old Second Bancorp, Inc. Common Stock 182 17 Feb 2026 By Profit Sharing Plan
holding OSBC Old Second Bancorp, Inc. Common Stock 1,450 17 Feb 2026 Spouse's IRA F4
* An asterisk sign (*) next to the price indicates that the price is likely invalid.

Explanation of Responses:

Id Content
F1 Each restricted stock unit represents a contingent right to receive one share of common stock. The reporting person was granted 11,292 restricted stock units on the date of the grant, 5,646 of which are time-based restricted stock units that vest on the third anniversary of the grant date, and 5,646 of which are performance-based restricted stock units that may vest and convert to shares within a range from 0% to 175% of the underlying performance-based restricted stock units originally awarded, depending on our compensation committee approved performance metrics. Vested shares, if any, will be delivered to the reporting person in 3 to 5 business days from the date of vesting.
F2 Represents shares withheld by the issuer to satisfy applicable tax withholding obligations in connection with the vesting of 5,256 previously reported time-based restricted stock units, the remaining shares of which were issued and added to the reporting person's common stock holdings.
F3 These shares are held in Mr. Pilmer's name outright.
F4 These shares are held in spouse's IRA for which Mr. Pilmer is listed as a beneficiary.