Kumi Yamamoto Baruffi - 13 Mar 2026 Form 4 Insider Report for COLUMBIA BANKING SYSTEM, INC. (COLB)

Role
EVP General Counsel, Corp Sec
Signature
/s/ Andrea M. Newburn, Attorney-in-fact
Issuer symbol
COLB
Transactions as of
13 Mar 2026
Net transactions value
-$24,578
Form type
4
Filing time
17 Mar 2026, 20:26:13 UTC
Previous filing
02 Mar 2026
SEC
View on sec.gov

Reporting Owners (1)

Name Relationship Address Signature Signature date CIK
BARUFFI KUMI YAMAMOTO EVP General Counsel, Corp Sec C/O COLUMBIA BANKING SYSTEM, INC., 1301 A STREET, TACOMA /s/ Andrea M. Newburn, Attorney-in-fact 17 Mar 2026 0001619728

Transactions Table

Type Sym Class Transaction Value $ Shares Change % * Price $ Shares After Date Ownership Footnotes
transaction COLB Common Stock Options Exercise +2,381 +4.6% $26.23* 54,652 13 Mar 2026 Direct
transaction COLB Common Stock Sale $24,578 -937 -1.7% $26.23 53,715 13 Mar 2026 Direct

Derivative Securities (e.g., puts, calls, warrants, options, convertible securities)

Type Sym Class Transaction Value $ Shares Change % * Price $ Shares After Date Underlying Class Amount Exercise Price Ownership Footnotes
transaction COLB Restricted Stock Unit Options Exercise -2,381 -15% $0.000000* 13,083 13 Mar 2026 Common Stock 2,381 Direct F1
* An asterisk sign (*) next to the price indicates that the price is likely invalid.

Explanation of Responses:

Id Content
F1 Restricted Stock Units convert into common stock on a one-for-one basis. On February 25, 2025, the reporting person was granted 7,142 Restricted Stock Units, which vest in three annual installments beginning on March 13, 2026.