Lakely Brock 4/A

What Happened
Lakely Brock, EVP and Chief Accounting Officer of Columbia Banking System, had 211 shares withheld by the issuer to satisfy tax obligations in connection with equity award vesting. The withholding was recorded at $26.23 per share for a total value of $5,535. This is a routine tax-withholding disposition (not an open-market sale).

Key Details

• Transaction date: 2026-03-13; price per share: $26.23; total value: $5,535.
• Transaction code: F (shares withheld to satisfy tax obligations). The original Form 4 filed 2026-03-17 incorrectly used code S and was amended on 2026-03-20 to correct this.
• Shares owned after the transaction: not specified in this filing.
• Timeliness: Original Form 4 was filed on March 17 (timely); this filing is an amendment to correct the transaction code.

Context
Tax-withholding dispositions are common when equity awards vest and generally reflect routine administrative actions rather than a deliberate market sale. This transaction does not, by itself, indicate insider sentiment about the company’s stock.