Pilmer Donald 4

4 · OLD SECOND BANCORP INC · Filed Mar 4, 2026

Form 4

Period: 2026-03-02

EVP

Transactions

Award
Old Second Bancorp, Inc. Common Stock
[F1]
2026-03-02+9,201→ 66,573 total
Tax Payment
Old Second Bancorp, Inc. Common Stock
[F2][F3]
2026-03-02$19.91/sh−2,720$54,155→ 73,054 total

Holdings

Footnotes (4)

[F1]Shares delivered to the reporting person pursuant to vesting of performance-based restricted stock units granted under the Old Second Bancorp, Inc. 2019 Equity Incentive Plan, as Amended and Restated and vested upon achievement of performance goals for the applicable performance period. The reporting person reported an acquisition of 5,256 on Form 4 filed February 21, 2023, which represented the number of shares that would be delivered if target performance was achieved during the performance period. Actual performance exceeded the target performance for the performance period which resulted in an additional grant of 3,945 shares.
[F2]Represents shares withheld by the issuer to satisfy applicable tax withholding obligations in connection with the vesting of 9,201 previously reported performance-based restricted stock units, the remaining shares of which were issued and added to the reporting person's common stock holdings.
[F3]Included in this total are 9,919 shares in the reporting person's name outright and 63,135 shares held in the reporting person's name in a brokerage account.
[F4]These shares are held in the reporting person's spouse's IRA for which the reporting person is listed as a beneficiary.

Signature

/s/ Shirley Cantrell, Attorney-in-Fact|2026-03-04

Documents

1 file