๐Ÿ•ต๏ธ Columbia Banking System, Inc. ($COLB)

SEC insider & ownership activity, last 12 months ยท CIK 887343 ยท every row links its SEC filing

Over the last 12 months insiders sold $677K against $22K of open-market buying. Steven R. Gardner sold $404K in discretionary trades (Jan). No red-flag 8-Ks in the window.

๐Ÿšจ 1 signal active โ€” planned-vs-executed verdicts, pre-event flags, and cluster context live in the API and the alerts bot.
Oct 2025: net +$0 Nov 2025: net +$0 Dec 2025: net +$0 Jan 2026: net -$404K Feb 2026: net +$0 Mar 2026: net -$158K Apr 2026: net +$0 May 2026: net +$0 Jun 2026: net -$93K Jul 2026: net +$0 Aug 2026: net +$0 Sep 2026: net +$0
Monthly net open-market insider flow, last 12 months (up = net buying)

Insider flow

1 buyer, $22K (1 lots) ยท 5 sellers, $677K (7 lots)

InsiderBuysBoughtSellsSoldLast
Steven R. Gardner0โ€“ 1$404KJan 30, 2026
Torran B. Nixon0โ€“ 2$128KMar 4, 2026
Moore Devine David0โ€“ 2$115KJun 8, 2026
Baruffi Kumi Yamamoto0โ€“ 1$25KMar 13, 2026
Deer Aaron James1$22K 0โ€“Jun 30, 2026
Lakely Brock0โ€“ 1$6KMar 13, 2026

5%+ holders

HolderStakeClassScheduleEvent
Wellington Management Company LLP 5.8% 13GFeb 10, 2026 filing โ†—
Vanguard Capital Management 5.2% 13GApr 29, 2026 filing โ†—

Planned insider sales (Form 144)

SellerPlannedApprox. sale date
Moore Devine David$115KJun 8, 2026 filing โ†—
Torran B. Nixon$65KMar 4, 2026 filing โ†—
Torran B. Nixon$63KMar 3, 2026 filing โ†—
Steven R. Gardner$404KJan 30, 2026 filing โ†—

Material events (8-K)

ItemEvent date
Other events (8.01)Aug 14, 2026 filing โ†—
Financial Statements and Exhibits (9.01)Aug 14, 2026 filing โ†—
Officer/director changes (5.02)Jul 28, 2026 filing โ†—
Reg FD disclosure (7.01)Jul 28, 2026 filing โ†—
Financial Statements and Exhibits (9.01)Jul 28, 2026 filing โ†—
Earnings (2.02)Jul 23, 2026 filing โ†—
Reg FD disclosure (7.01)Jul 23, 2026 filing โ†—
Financial Statements and Exhibits (9.01)Jul 23, 2026 filing โ†—
Reg FD disclosure (7.01)Jun 30, 2026 filing โ†—
Financial Statements and Exhibits (9.01)Jun 30, 2026 filing โ†—
Other events (8.01)May 15, 2026 filing โ†—
Financial Statements and Exhibits (9.01)May 15, 2026 filing โ†—
Shareholder vote (5.07)May 14, 2026 filing โ†—
Earnings (2.02)Apr 23, 2026 filing โ†—
Reg FD disclosure (7.01)Apr 23, 2026 filing โ†—
Financial Statements and Exhibits (9.01)Apr 23, 2026 filing โ†—
Reg FD disclosure (7.01)Mar 31, 2026 filing โ†—
Financial Statements and Exhibits (9.01)Mar 31, 2026 filing โ†—
Other events (8.01)Feb 13, 2026 filing โ†—
Financial Statements and Exhibits (9.01)Feb 13, 2026 filing โ†—
Earnings (2.02)Jan 22, 2026 filing โ†—
Reg FD disclosure (7.01)Jan 22, 2026 filing โ†—
Financial Statements and Exhibits (9.01)Jan 22, 2026 filing โ†—
Reg FD disclosure (7.01)Dec 31, 2025 filing โ†—
Financial Statements and Exhibits (9.01)Dec 31, 2025 filing โ†—
Officer/director changes (5.02)Nov 19, 2025 filing โ†—
Other events (8.01)Nov 14, 2025 filing โ†—
Financial Statements and Exhibits (9.01)Nov 14, 2025 filing โ†—
Earnings (2.02)Oct 30, 2025 filing โ†—
Reg FD disclosure (7.01)Oct 30, 2025 filing โ†—