KRRO (Korro Bio, Inc. Common Stock)
Insider Trading Activity
Every open-market purchase and sale reported by KRRO officers, directors and 10%+ beneficial owners on SEC Form 4, which must be filed within two business days of the transaction. Sales often reflect scheduled 10b5-1 plans or tax withholding rather than a directional view, so read counts alongside the size and the filer.
Market data may be delayed, incomplete, or inaccurate. Not a recommendation to buy, sell, or hold any security. Verify quotes with your broker before trading. See Terms §17.
| Filed | Insider | Role | Type | Shares | Value |
|---|---|---|---|---|---|
| 2026-08-28 | JEAN FRANCOIS FORMELA | Director | Sell | — | — |
| 2026-08-21 | JEAN FRANCOIS FORMELA | Director | Sell | — | — |
| 2026-08-13 | Weston Nichols | 10%+ Owner | Buy | — | — |
| 2026-08-13 | JEAN FRANCOIS FORMELA | Director | Sell | — | — |
| 2026-08-05 | Ram Aiyar | President and CEO | Sell | — | — |
| 2026-07-17 | Loic A Vincent | Chief Scientific Officer | A | — | — |
| 2026-07-17 | Todd Chappell | Chief Operating Officer | A | — | — |
| 2026-07-17 | Oliver Dolan | Senior Vice President, Finance | A | — | — |
| 2026-07-17 | Jeffrey Cerio | General Counsel | A | — | — |
| 2026-07-07 | JEAN FRANCOIS FORMELA | Director | Sell | — | — |
| 2026-06-24 | JEAN FRANCOIS FORMELA | Director | Sell | — | — |
| 2026-06-17 | Loic A Vincent | Chief Scientific Officer | Sell | — | — |
| 2026-06-17 | Todd Chappell | Chief Operating Officer | Sell | — | — |
| 2026-06-17 | Jeffrey Cerio | General Counsel | Sell | — | — |
| 2026-06-17 | Oliver Dolan | Senior Vice President, Finance | Sell | — | — |
| 2026-06-11 | Rachel Meyers | Director | A | — | — |
| 2026-06-11 | JEAN FRANCOIS FORMELA | Director | A | — | — |
| 2026-06-11 | Ali Behbahani | Director | A | — | — |
| 2026-06-11 | Katharine Knobil | Director | A | — | — |
| 2026-06-11 | Nessan Bermingham | Director | A | — | — |
| 2026-06-11 | TIMOTHY R PEARSON | Director | A | — | — |
| 2026-06-02 | Ram Aiyar | President and CEO | Sell | — | — |
| 2026-06-01 | JEAN FRANCOIS FORMELA | Director | Sell | — | — |
| 2026-05-28 | Ram Aiyar | President and CEO | A | — | — |
| 2026-04-02 | Weston Nichols | 10%+ Owner | Buy | — | — |
| 2026-03-12 | Rick Yang | 10%+ Owner | Buy | — | — |
| 2026-03-12 | Anthony A. Florence Jr. | 10%+ Owner | Buy | — | — |
| 2026-03-12 | Ali Behbahani | Director | A | — | — |
| 2026-03-12 | Edward T Mathers | 10%+ Owner | Buy | — | — |
| 2026-03-12 | FOREST BASKETT | 10%+ Owner | Buy | — | — |
| 2026-03-12 | Paul Edward Walker | 10%+ Owner | Buy | — | — |
| 2026-03-12 | SCOTT D SANDELL | 10%+ Owner | Buy | — | — |
| 2026-03-12 | NEA 17 GP, LLC | 10%+ Owner | Buy | — | — |
| 2026-03-12 | Carmen Chang | 10%+ Owner | Buy | — | — |
| 2026-03-12 | Mohamad Makhzoumi | 10%+ Owner | Buy | — | — |
| 2026-02-03 | Jeffrey Cerio | General Counsel | A | — | — |
| 2026-02-03 | Todd Chappell | Chief Operating Officer | A | — | — |
| 2026-02-03 | Oliver Dolan | Senior Vice President, Finance | A | — | — |
| 2026-02-03 | Loic A Vincent | Chief Scientific Officer | A | — | — |
| 2026-02-03 | Ram Aiyar | President and CEO | A | — | — |
| 2025-12-16 | Oliver Dolan | Senior Vice President, Finance | A | — | — |
| 2025-12-16 | Jeffrey Cerio | General Counsel | A | — | — |
| 2025-12-16 | Loic A Vincent | Chief Scientific Officer | A | — | — |
| 2025-12-16 | Todd Chappell | Chief Operating Officer | A | — | — |
| 2025-06-12 | Nessan Bermingham | Director | A | — | — |
| 2025-06-12 | JEAN FRANCOIS FORMELA | Director | A | — | — |
| 2025-06-12 | TIMOTHY R PEARSON | Director | A | — | — |
| 2025-06-12 | Rachel Meyers | Director | A | — | — |
| 2025-06-12 | Ali Behbahani | Director | A | — | — |
| 2025-06-12 | Katharine Knobil | Director | A | — | — |
| Insider | Role | Shares Held | Value |
|---|---|---|---|
| — | 10%+ Owner | 1,544,980 | — |
| — | 10%+ Owner | 1,297,893 | — |
| — | 10%+ Owner | 1,297,893 | — |
| — | 10%+ Owner | 1,297,893 | — |
| — | 10%+ Owner | 1,297,893 | — |
| — | 10%+ Owner | 1,297,893 | — |
| — | Director | 1,297,893 | — |
| — | 10%+ Owner | 1,297,893 | — |
| — | 10%+ Owner | 1,297,893 | — |
| — | 10%+ Owner | 1,297,893 | — |
| — | 10%+ Owner | 1,297,893 | — |
| — | 10%+ Owner | 195,074 | — |
| — | Director | 141,002 | — |
| — | President and CEO | 73,659 | — |
| — | General Counsel | 41,793 | — |
| — | Chief Scientific Officer | 25,797 | — |
| — | Chief Operating Officer | 24,464 | — |
| — | Senior Vice President, Finance | 23,599 | — |
| — | Director | 22,150 | — |
| — | Chief Financial Officer | 800 | — |
Form 4 reports a change in beneficial ownership by an officer, director or 10%+ holder, and must be filed within two business days of the transaction — so this is close to real time, unlike the 45-day-lagged 13F institutional data.
Transaction codes matter more than the raw buy/sell count. Code P is an open-market purchase — an insider choosing to buy with their own money, which is the signal most research treats as informative. Code S is a sale, but sales are frequently pre-scheduled under a 10b5-1 plan or cover tax withholding on vesting equity, so a run of sales often says nothing directional. Codes A and M are grants and option exercises rather than open-market decisions.
Full filing history and per-insider positions are on the KRRO quote page; the site-wide leaderboard is on the insider transactions hub.