InsiderTrades

Form 4 for COLB COLUMBIA BANKING SYSTEM, INC.

Accepted 2026-03-17 00:00:00 ET · period of report 2026-03-13 · accession 0001955918-26-000003 · 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 Anderson Drew K EVP Chief Admin Off F - Tax $26.23 -1,215 22.0K -5% -$31.9K
D 2026-03-17 2026-03-13 COLB Anderson Drew K EVP Chief Admin Off M - OptEx $26.23 +2,506 23.2K +12% +$65.7K
D 2026-03-17 2026-03-13 COLB Anderson Drew K EVP Chief Admin Off M - OptEx $0.00 -2,506 50.6K -5% $0

Purchase Sale Sale after option exercise All abbreviations

Every reported transaction

#TableSecurityDateCodeA/DSharesPriceOwned afterOwnExercise / expiryUnderlyingFootnotes
1 Common Common Stock 2026-03-13 F D 1,215 $26.23 21,969 D — —
2 Common Common Stock 2026-03-13 M A 2,506 $26.23 23,184 D — —
3 Derivative Restricted Stock Unit 2026-03-13 M D 2,506 $0.00 50,607 D — · — to — 2,506 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 7,518 Restricted Stock Units, which vest in three annual installments beginning on March 13, 2026.