CGEM (Cullinan Therapeutics, Inc. Common Stock)
Insider Trading Activity
Every open-market purchase and sale reported by CGEM 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 |
|---|---|---|---|---|---|
| 2026-09-10 | Jennifer Michaelson | Chief Scientific Officer | MIXED | — | — |
| 2026-08-14 | Jennifer Michaelson | Chief Scientific Officer | MIXED | — | — |
| 2026-07-07 | Jennifer Michaelson | Chief Scientific Officer | MIXED | — | — |
| 2026-07-02 | JACQUELYN L SUMER | Chief Legal Officer | A | — | — |
| 2026-07-02 | Mary Kay Fenton | Chief Financial Officer | A | — | — |
| 2026-06-18 | Stephen W Webster | Director | A | — | — |
| 2026-06-18 | Mittie Doyle | Director | A | — | — |
| 2026-06-18 | Mary Thistle | Director | A | — | — |
| 2026-06-18 | David D. Meek | Director | A | — | — |
| 2026-06-18 | Anthony Rosenberg | Director | A | — | — |
| 2026-06-18 | Andrew R Allen | Director | A | — | — |
| 2026-05-06 | Jennifer Michaelson | Chief Scientific Officer | MIXED | — | — |
| 2026-03-09 | Jennifer Michaelson | Chief Scientific Officer | MIXED | — | — |
| 2026-02-26 | Jennifer Michaelson | Chief Scientific Officer | Sell | — | — |
| 2026-02-25 | NADIM AHMED | President and CEO | Sell | — | — |
| 2026-02-25 | Jennifer Michaelson | Chief Scientific Officer | Sell | — | — |
| 2026-02-25 | Jeffrey Alan Jones | Chief Medical Officer | Sell | — | — |
| 2026-02-25 | JACQUELYN L SUMER | Chief Legal Officer | Sell | — | — |
| 2026-02-23 | NADIM AHMED | President and CEO | Sell | — | — |
| 2026-02-23 | Jennifer Michaelson | Chief Scientific Officer | MIXED | — | — |
| 2026-02-23 | Jeffrey Alan Jones | Chief Medical Officer | Sell | — | — |
| 2026-02-23 | JACQUELYN L SUMER | Chief Legal Officer | Sell | — | — |
| 2026-02-23 | Mary Kay Fenton | Chief Financial Officer | Sell | — | — |
| 2026-02-19 | Corrine Savill | Chief Business Officer | A | — | — |
| 2026-02-19 | Jennifer Michaelson | Chief Scientific Officer | A | — | — |
| 2026-02-19 | Jeffrey Alan Jones | Chief Medical Officer | A | — | — |
| 2026-02-19 | Mary Kay Fenton | Chief Financial Officer | A | — | — |
| 2026-02-19 | NADIM AHMED | President and CEO | A | — | — |
| 2026-02-19 | JACQUELYN L SUMER | Chief Legal Officer | A | — | — |
| 2026-02-13 | Jennifer Michaelson | Chief Scientific Officer | Sell | — | — |
| 2026-01-23 | Jennifer Michaelson | Chief Scientific Officer | Sell | — | — |
| 2026-01-05 | Mary Kay Fenton | Chief Financial Officer | A | — | — |
| 2025-12-29 | NADIM AHMED | President and CEO | Sell | — | — |
| 2025-12-22 | Jennifer Michaelson | Chief Scientific Officer | Sell | — | — |
| 2025-12-19 | JACQUELYN L SUMER | Chief Legal Officer | Sell | — | — |
| 2025-12-19 | Jeffrey Alan Jones | Chief Medical Officer | Sell | — | — |
| 2025-12-19 | Jennifer Michaelson | Chief Scientific Officer | Sell | — | — |
| 2025-12-16 | Jennifer Michaelson | Chief Scientific Officer | Sell | — | — |
| 2025-11-25 | Jennifer Michaelson | Chief Scientific Officer | Sell | — | — |
| 2025-10-30 | Lynx1 Capital Management LP | 10%+ Owner | Buy | — | — |
| 2025-10-21 | Lynx1 Capital Management LP | 10%+ Owner | Buy | — | — |
| 2025-10-10 | Lynx1 Capital Management LP | 10%+ Owner | Buy | — | — |
| 2025-08-08 | Mittie Doyle | Director | A | — | — |
| 2025-08-08 | Andrew R Allen | Director | A | — | — |
| 2025-06-16 | Anne-Marie Martin | Director | A | — | — |
| 2025-06-16 | David P. Ryan | Director | A | — | — |
| 2025-06-16 | David D. Meek | Director | A | — | — |
| 2025-06-16 | Anthony Rosenberg | Director | A | — | — |
| 2025-06-16 | Stephen W Webster | Director | A | — | — |
| 2025-02-27 | NADIM AHMED | President and CEO | Sell | — | — |
| Insider | Role | Shares Held | Value |
|---|---|---|---|
| — | 10%+ Owner | 8,963,500 | — |
| — | Director | 7,892,819 | — |
| — | 10%+ Owner | 7,858,018 | — |
| — | 10%+ Owner | 7,657,817 | — |
| — | 10%+ Owner | 7,648,268 | — |
| — | 10%+ Owner | 2,196,240 | — |
| — | 10%+ Owner | 1,508,884 | — |
| — | 10%+ Owner | 751,802 | — |
| — | Director | 578,214 | — |
| — | President and CEO | 506,226 | — |
| — | Chief Scientific Officer | 417,434 | — |
| — | — | 392,808 | — |
| — | President and CEO | 390,803 | — |
| — | — | 364,161 | — |
| — | Chief Business Officer | 240,990 | — |
| — | Director | 186,653 | — |
| — | Chief Scientific Officer | 162,844 | — |
| — | Chief Medical Officer | 159,968 | — |
| — | Chief Financial Officer | 133,919 | — |
| — | Chief Legal Officer | 130,559 | — |
| — | Chief Financial Officer | 127,921 | — |
| — | See Remarks | 69,785 | — |
| — | Chief Legal Officer | 24,124 | — |
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 CGEM quote page; the site-wide leaderboard is on the insider transactions hub.