Torran B. Nixon - Mar 4, 2025 Form 4 Insider Report for COLUMBIA BANKING SYSTEM, INC. (COLB)

Role: Senior Executive VP
Signature: /s/ Lisa M. White, Attorney-in-fact
Stock symbol: COLB
Transactions as of: Mar 4, 2025
Transactions value $: -$116,461
Form type: 4
Date filed: 3/5/2025, 06:10 PM
Previous filing: Mar 4, 2025
SEC: View on sec.gov

Transactions Table

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Ownership	Footnotes
transaction	COLB	Common Stock	Sale	-$116K	-4.48K	-4.1%	$25.99	105K	Mar 4, 2025	Direct	F1
holding	COLB	Common Stock						3.65K	Mar 4, 2025	by Nixon Family Trust
holding	COLB	Common Stock						1.59K	Mar 4, 2025	by 401(k)

* An asterisk sign (*) next to the price indicates that the price is likely invalid.

Buy Plan / Sale Plan: These are also open market purchases/sales of shares, but in this case the transaction is part of a trading plan. Rule 10b5-1 allows insiders to setup a trading plan to buy/sell stocks over a certain period of time. Since the purchases/sales are predetermined, this protects the insiders from violating insider trading law.

Transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c).

Explanation of Responses:

Id	Content
F1	Open market sale pursuant to a 10B5-1 Plan which was established by Reporting Person on December 3, 2024, in accordance with Rule 10B5-1 of the Securities Exchange Act of 1934, as amended.