Columbia (NASDAQ: COLB) EVP logs 1,808-share tax-withholding disposition

Rhea-AI Filing Summary

Columbia Banking System reported an insider equity transaction involving EVP Chief Credit Officer Frank Namdar. On March 1, 2026, Namdar had 1,808 shares of common stock disposed of at $28.45 per share as a tax-withholding disposition, rather than an open-market sale. After this transaction, he directly owned 30,470 common shares. The filing also notes an additional 4,146 shares held indirectly through a 401(k) plan, reflecting retirement-related ownership separate from his direct holdings.

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

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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^*

Namdar Frank

(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)
	EVP Chief Credit Officer

3. Date of Earliest Transaction (Month/Day/Year)
03/01/2026

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	03/01/2026		F		1,808	D	$28.45	30,470	D
Common Stock								4,146	I	by 401(k)

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

Explanation of Responses:

Remarks:

	/s/ Andrea M. Newburn, Attorney-in-fact	03/02/2026
	** 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 report for Frank Namdar on this Form 4?

The filing shows EVP Chief Credit Officer Frank Namdar had 1,808 COLB common shares disposed of at $28.45 per share to cover tax obligations. This was a tax-withholding disposition, not an open-market purchase or sale of stock.

Was the COLB Form 4 transaction an open-market sale of shares?

No, the COLB Form 4 describes a tax-withholding disposition, coded “F,” rather than an open-market sale. 1,808 shares were used to satisfy tax liabilities associated with equity compensation, so it does not represent a discretionary sale into the market.

How many COLB shares does Frank Namdar own after the reported transaction?

After the tax-withholding disposition, Frank Namdar directly owns 30,470 COLB common shares. The Form 4 also reports an additional 4,146 shares held indirectly through a 401(k) plan, which reflects retirement-plan holdings separate from his direct ownership position.

What is Frank Namdar’s role at Columbia Banking System (COLB)?

Frank Namdar serves as EVP Chief Credit Officer of Columbia Banking System. This senior executive position oversees credit risk and lending quality. His Form 4 filing details how his COLB equity awards generated a tax-withholding share disposition on March 1, 2026.

What does transaction code “F” mean in the COLB Form 4 for Frank Namdar?

Transaction code “F” indicates a payment of tax liability by delivering securities. In this COLB filing, 1,808 shares of common stock were disposed of at $28.45 per share to cover taxes arising from equity compensation, rather than being sold voluntarily on the market.