InsiderTrades

Form 4 for COLB COLUMBIA BANKING SYSTEM, INC.

Accepted 2026-03-17 00:00:00 ET · period of report 2026-03-13 · accession 0001619728-26-000003 · 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 BARUFFI KUMI YAMAMOTO EVP GC, Corp Sec S - Sale+OE $26.23 -937 53.7K -2% -$24.6K
D 2026-03-17 2026-03-13 COLB BARUFFI KUMI YAMAMOTO EVP GC, Corp Sec M - OptEx $26.23 +2,381 54.7K +5% +$62.5K
D 2026-03-17 2026-03-13 COLB BARUFFI KUMI YAMAMOTO EVP GC, Corp Sec M - OptEx $0.00 -2,381 13.1K -15% $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 937 $26.23 53,715 D — —
2 Common Common Stock 2026-03-13 M A 2,381 $26.23 54,652 D — —
3 Derivative Restricted Stock Unit 2026-03-13 M D 2,381 $0.00 13,083 D — · — to — 2,381 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 7,142 Restricted Stock Units, which vest in three annual installments beginning on March 13, 2026.