Columbia Banking (NASDAQ: COLB) EVP exercises 5,013 RSUs, 1,973 shares withheld for taxes

Rhea-AI Filing Summary

Columbia Banking System Senior Executive VP Christopher Merrywell exercised 5,013 Restricted Stock Units into common stock on March 13, 2026. The units converted one-for-one into shares, valued at $26.23 per share for this transaction. To cover tax obligations, 1,973 shares were withheld, leaving him with 44,067 common shares directly owned after the transactions.

Insider Trade Summary

5,013 shares exercised/converted

Mixed 3 txns

Insider Merrywell Christopher

Role Senior Executive VP

Type	Security	Shares	Price	Value
Exercise	Restricted Stock Unit	5,013	$0.00	--
Exercise	Common Stock	5,013	$26.23	$131K
Tax Withholding	Common Stock	1,973	$26.23	$52K

Holdings After Transaction: Restricted Stock Unit — 51,291 shares (Direct); Common Stock — 46,040 shares (Direct)

Footnotes (1)

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Form 4 Insider Transactions: What Each Field Means →

SEC Form 4

FORM 4

UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940

OMB APPROVAL

OMB Number:			3235-0287
Estimated average burden
hours per response:			0.5

Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

Check this box to indicate that a 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). See Instruction 10.

1. Name and Address of Reporting Person^*

Merrywell Christopher

(Last) (First) (Middle)

C/O COLUMBIA BANKING SYSTEM, INC.

1301 A STREET

(Street)

TACOMA WA 98402

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
COLUMBIA BANKING SYSTEM, INC. [ COLB ]

5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

	Director		10% Owner
X	Officer (give title below)		Other (specify below)
	Senior Executive VP

3. Date of Earliest Transaction (Month/Day/Year)
03/13/2026

4. If Amendment, Date of Original Filed (Month/Day/Year)

6. Individual or Joint/Group Filing (Check Applicable Line)

X	Form filed by One Reporting Person
	Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	3. Transaction Code (Instr. 8)		4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
			Code	V	Amount	(A) or (D)	Price
Common Stock	03/13/2026		M		5,013	A	$26.23	46,040	D
Common Stock	03/13/2026		F		1,973	D	$26.23	44,067	D

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	4. Transaction Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares
Restricted Stock Unit	(1)	03/13/2026		M			5,013	(1)	(1)	Common Stock	5,013	$0	51,291	D

Explanation of Responses:

1. Restricted Stock Units convert into common stock on a one-for-one basis. On February 25, 2025, the reporting person was granted 15,037 Restricted Stock Units, which vest in three annual installments beginning on March 13, 2026.

Remarks:

	/s/ Andrea M. Newburn, Attorney-in-fact	03/17/2026
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.

FAQ

What insider transaction did COLB executive Christopher Merrywell report?

Christopher Merrywell reported exercising 5,013 Restricted Stock Units into common stock on March 13, 2026. These RSUs converted one-for-one into Columbia Banking System shares as part of a previously granted equity award vesting schedule.

How many COLB shares were withheld for taxes in Merrywell’s Form 4?

The filing shows 1,973 common shares were withheld at $26.23 per share to satisfy tax obligations. This tax-withholding disposition is coded "F" and is not an open-market sale, but a mechanism to pay required taxes.

How many Columbia Banking System shares does Merrywell hold after these transactions?

After the March 13, 2026 transactions, Merrywell directly holds 44,067 shares of common stock. This figure reflects the net position after exercising 5,013 RSUs and having 1,973 shares withheld to cover tax liabilities associated with the vesting.

What does the Form 4 say about the terms of Merrywell’s Restricted Stock Units at COLB?

A footnote states Merrywell was granted 15,037 Restricted Stock Units on February 25, 2025. These units vest in three equal annual installments beginning March 13, 2026, with each vested portion converting into common stock on a one-for-one basis.

Were Merrywell’s COLB transactions open-market buys or sells?

The Form 4 reports an exercise of derivative securities and a tax-withholding disposition, not open-market trades. Code "M" reflects RSU conversion into shares, while code "F" represents shares withheld to pay taxes rather than voluntary market sales.