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Columbia Banking System stock timeline
A year of the price with every insider trade, planned sale, earnings report and material 8-K marked
252 sessions+21.2% to $30.48
Columbia Banking System (COLB) stock rose 21% over the last 252 sessions, to $30.48. On the way it reported 0 quarters, its insiders filed 5 open-market trades and 1 Form 144 notice of planned sales, and the company filed 3 material 8-Ks. Each is marked on the price and listed with what the stock did next.
Each mark, and what followed
| Date | Kind | What | Next session | 5 sessions | 21 sessions |
|---|---|---|---|---|---|
| Oct 29, 2026 | Form 144 | Form 144: Steven R Gardner plans to sell $329K | +0.9% (+1.3% vs SPY) | +2.1% (+2.8% vs SPY) | — |
| Oct 29, 2026 | Insider sale | Gardner Steven R sold $15K | +0.9% (+1.3% vs SPY) | +2.1% (+2.8% vs SPY) | — |
| Oct 27, 2026 | 8-K | Directors and officers: departures, appointments, pay | −1.0% (−1.4% vs SPY) | −0.7% (+1.4% vs SPY) | — |
| Jul 30, 2026 | 8-K | Directors and officers: departures, appointments, pay | +0.1% (−0.7% vs SPY) | −0.7% (−4.3% vs SPY) | −2.7% (−6.3% vs SPY) |
| Jun 30, 2026 | Insider buy | Deer Aaron James bought $22K | +0.2% (−0.6% vs SPY) | +0.4% (−0.5% vs SPY) | −3.9% (−2.3% vs SPY) |
| Jun 8, 2026 | Insider sale | Moore Devine David sold $115K | +0.1% (−0.2% vs SPY) | +5.4% (+4.8% vs SPY) | +5.3% (+4.0% vs SPY) |
| Mar 13, 2026 | Insider sale | Baruffi Kumi Yamamoto sold $25K | −0.7% (−0.2% vs SPY) | 0.0% (+0.9% vs SPY) | +9.9% (+6.6% vs SPY) |
| Jan 30, 2026 | Insider sale | Gardner Steven R sold $404K | +1.4% (+1.7% vs SPY) | +7.3% (+9.7% vs SPY) | +1.2% (+2.3% vs SPY) |
| Nov 21, 2025 | 8-K | Directors and officers: departures, appointments, pay | +3.5% (+2.5% vs SPY) | +6.8% (+2.2% vs SPY) | +11.4% (+6.3% vs SPY) |
Insiders’ record here
In the year on the chart, Columbia Banking System's insiders reported 1 open-market buy ($22K) and 4 sales ($559K). Of the 4 old enough to score, 2 were followed by the stock doing what the trade implied over the next 63 sessions (beating SPY after a buy, lagging it after a sale); the median excess return after a buy was −12.8% and after a sale −1.6%.
Across the whole universe (19,782 scored trades), insider buys beat the market 46% of the time and sales were followed by a lagging stock 61% of the time; buys of $1M or more 39%. Every pattern →
What this kind of 8-K usually did
| Item | 8-Ks | Next session, median | Up next session | 21 sessions, median | Typical size |
|---|---|---|---|---|---|
| 5.02 Directors and officers: departures, appointments, pay | 39,174 | −0.1% | 48% | +0.7% | ±1.4% |
Across every company in the move-odds universe, measured from the close before the filing. Every 8-K item ranked →
Columbia Banking System: every quarter → Live insider trades →
Prices are daily closes; filings and trades are as filed with the SEC (Form 4 within two business days of the trade, 8-K within four of the event). Moves after a mark are the stock's close-to-close change and the same for SPY; they describe the record, not what the next one will do. Not investment advice.