InsiderTrades

Form 4 for COLB COLUMBIA BANKING SYSTEM, INC.

Accepted 2026-03-17 00:00:00 ET · period of report 2026-03-13 · accession 0001759802-26-000008 · SEC index · Original document

Summary rows

Aggregated the way they appear in lists: one row per insider, transaction code and security table.

X Filed Traded Ticker Insider Title Type Price Qty Owned ΔOwn Value
D 2026-03-17 2026-03-13 COLB Namdar Frank EVP Chief Credit Off M - OptEx $26.23 +2,820 33.3K +9% +$74.0K
D 2026-03-17 2026-03-13 COLB Namdar Frank EVP Chief Credit Off F - Tax $26.23 -1,367 31.9K -4% -$35.9K
D 2026-03-17 2026-03-13 COLB Namdar Frank EVP Chief Credit Off M - OptEx $0.00 -2,820 13.6K -17% $0

Purchase Sale Sale after option exercise All abbreviations

Every reported transaction

#TableSecurityDateCodeA/DSharesPriceOwned afterOwnExercise / expiryUnderlyingFootnotes
1 Common Common Stock 2026-03-13 M A 2,820 $26.23 33,290 D — —
2 Common Common Stock 2026-03-13 F D 1,367 $26.23 31,923 D — —
3 Derivative Restricted Stock Unit 2026-03-13 M D 2,820 $0.00 13,640 D — · — to — 2,820 Common Stock (F1) Restricted Stock Units convert into common stock on a one-for-one basis. On February 25, 2025, the reporting person was granted 8,458 Restricted Stock Units, which vest in three annual installments beginning on March 13, 2026.