Columbia Banking (NASDAQ: COLB) EVP logs tax-withholding share disposition

Rhea-AI Filing Summary

Columbia Banking System executive reports tax-related share disposition

COLUMBIA BANKING SYSTEM, INC. executive officer Kumi Yamamoto Baruffi, EVP General Counsel and Corporate Secretary, reported a tax-withholding disposition of 1,799 shares of common stock at $28.45 per share. After this tax-related transaction, she directly holds 52,271 shares of Columbia Banking System common stock.

Insider Trade Summary

1 transaction reported

Mixed 1 txn

Insider BARUFFI KUMI YAMAMOTO

Role EVP General Counsel, Corp Sec

Type	Security	Shares	Price	Value
Tax Withholding	Common Stock	1,799	$28.45	$51K

Holdings After Transaction: Common Stock — 52,271 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^*

BARUFFI KUMI YAMAMOTO

(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 General Counsel, Corp Sec

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		1,799	D	$28.45	52,271	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

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 executive Kumi Yamamoto Baruffi report?

Kumi Yamamoto Baruffi reported a tax-withholding disposition of 1,799 shares of Columbia Banking System common stock. The shares were transferred at $28.45 per share to cover tax obligations related to equity compensation, rather than an open-market sale transaction.

What is the size of the reported Form 4 transaction for COLB?

The reported Form 4 transaction involves 1,799 shares of Columbia Banking System common stock. These shares were disposed of at $28.45 per share for tax-withholding purposes, reflecting a relatively small adjustment to the executive’s holdings rather than a large-scale share sale.

How many COLB shares does Kumi Yamamoto Baruffi hold after the transaction?

After the tax-withholding disposition, Kumi Yamamoto Baruffi directly holds 52,271 shares of Columbia Banking System common stock. This figure reflects her remaining direct ownership following the 1,799-share transfer made to satisfy tax liabilities tied to equity awards.

What does transaction code "F" mean in the COLB Form 4 filing?

Transaction code “F” indicates a tax-withholding disposition, where shares are delivered to pay the exercise price or tax liability. For COLB, the 1,799 shares were used to satisfy tax obligations on equity compensation, not as a discretionary open-market sale of stock.

Is the COLB insider transaction a buy or a sell of common stock?

The transaction is categorized as a disposition for tax withholding, not a typical open-market sale. Shares were transferred at $28.45 each to satisfy tax obligations, while the executive continues to directly own 52,271 shares of Columbia Banking System common stock afterward.