InsiderTrades

Form 4 for COLB COLUMBIA BANKING SYSTEM, INC.

Accepted 2026-03-17 00:00:00 ET · period of report 2026-03-13 · accession 0001740374-26-000002 · 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 Lakely Brock EVP, CAO S - Sale+OE $26.23 -211 11.1K -2% -$5,535
D 2026-03-17 2026-03-13 COLB Lakely Brock EVP, CAO M - OptEx $26.23 +846 11.3K +8% +$22.2K
D 2026-03-17 2026-03-13 COLB Lakely Brock EVP, CAO M - OptEx $0.00 -846 9,810 -8% $0

Purchase Sale Sale after option exercise All abbreviations

Every reported transaction

#TableSecurityDateCodeA/DSharesPriceOwned afterOwnExercise / expiryUnderlyingFootnotes
1 Common Common Stock 2026-03-13 S D 211 $26.23 11,104 D — —
2 Common Common Stock 2026-03-13 M A 846 $26.23 11,315 D — —
3 Derivative Restricted Stock Unit 2026-03-13 M D 846 $0.00 9,810 D — · — to — 846 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 2,537 Restricted Stock Units, which vest in three annual installments beginning on March 13, 2026.