THRD · Insider Trading
Third Harmonic Bio, Inc. Common Stock
Every open-market purchase and sale reported by THRD 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.
| Filed | Insider | Role | Type | Shares | Value |
|---|---|---|---|---|---|
| 2025-03-05 | Christopher M. Murphy | Chief Financial & Bus. Officer | A | +30,000 deriv. | — |
| 2025-01-17 | Jennifer Dittman | Chief Operating Officer | A | +103,500 deriv. | — |
| 2025-01-17 | Natalie C. Holles | CEO | A | +450,000 deriv. | — |
| 2025-01-17 | Dennis Dean | Chief Nonclinical Dev. Officer | A | +103,500 deriv. | — |
| 2025-01-17 | Edward R. Conner | Chief Medical Officer | A | +148,500 deriv. | — |
| 2025-01-17 | Julie Person | CHIEF ADMINISTRATIVE OFFICER | A | +112,500 deriv. | — |
| 2025-01-17 | Christopher M. Murphy | Chief Financial & Bus. Officer | A | +157,500 deriv. | — |
| 2025-01-17 | Christopher Dinsmore | Chief Scientific Officer | A | +130,500 deriv. | — |
| 2024-11-12 | Edward R. Conner | Chief Medical Officer | MIXED | — | −$22.86K |
| 2024-11-05 | Atlas Venture Fund XI, L.P. | 10%+ Owner | J | −515,688 | — |
| 2024-10-31 | BIOTECHNOLOGY VALUE FUND L P | — | Sell | −10,000,000 | −$143.00M |
| 2024-10-30 | Edward R. Conner | Chief Medical Officer | MIXED | — | −$28.87K |
| 2024-09-20 | Edward R. Conner | Chief Medical Officer | MIXED | — | −$51.73K |
| 2024-09-20 | Julie Person | CHIEF ADMINISTRATIVE OFFICER | MIXED | −18,994 | −$180.50K |
| 2024-06-28 | Christopher Dinsmore | Chief Scientific Officer | A | +297,000 deriv. | — |
| 2024-06-28 | Julie Person | CHIEF ADMINISTRATIVE OFFICER | MIXED | — | −$82.57K |
| 2024-06-10 | Hans Martin Seidel | Director | A | +20,000 deriv. | — |
| 2024-06-10 | David P Bonita | Director | A | +20,000 deriv. | — |
| 2024-06-10 | Thomas P Soloway | Director | A | +20,000 deriv. | — |
| 2024-06-10 | Mark T Iwicki | Director | A | +20,000 deriv. | — |
| 2024-06-10 | Michael Gladstone | Director | A | +20,000 deriv. | — |
| 2024-06-10 | Jennifer Dittman | Chief Development Oper Officer | MIXED | −988 | −$9.07K |
| 2024-05-22 | Jennifer Dittman | Chief Development Oper Officer | MIXED | −2,084 | −$19.07K |
| 2024-05-20 | Dennis Dean | Chief Nonclinical Dev. Officer | A | +210,000 deriv. | — |
| 2024-05-20 | Christopher Dinsmore | Chief Scientific Officer | A | +210,000 deriv. | — |
| 2024-05-20 | Jennifer Dittman | Chief Development Oper Officer | MIXED | — | −$230.37K |
| 2024-05-10 | Natalie C. Holles | CEO | MIXED | — | −$161.37K |
| 2024-04-15 | Natalie C. Holles | CEO | MIXED | — | −$108.27K |
| 2024-04-08 | Julie Person | CHIEF ADMINISTRATIVE OFFICER | MIXED | — | −$6.42K |
| 2024-03-28 | Geoff McDonough | Director | A | +60,000 deriv. | — |
| 2024-01-09 | Julie Person | Chief Administrative Officer | A | +116,000 deriv. | — |
| 2024-01-09 | Christopher M. Murphy | Chief Financial & Bus. Officer | A | +410,000 deriv. | — |
| 2024-01-09 | Edward R. Conner | Chief Medical Officer | A | +133,000 deriv. | — |
| 2024-01-09 | Natalie C. Holles | CEO | A | +396,000 deriv. | — |
| 2024-01-05 | Natalie C. Holles | CEO | A | +396,000 deriv. | — |
| 2023-12-07 | Edward R. Conner | Chief Medical Officer | MIXED | — | −$27.94K |
| 2023-12-07 | Julie Person | Chief Administrative Officer | MIXED | — | −$78.46K |
| 2023-06-08 | David P Bonita | Director | A | +16,250 deriv. | — |
| 2023-06-08 | Hans Martin Seidel | Director | A | +16,250 deriv. | — |
| 2023-06-08 | Thomas P Soloway | Director | A | +16,250 deriv. | — |
| 2023-06-08 | Mark T Iwicki | Director | A | +16,250 deriv. | — |
| 2023-06-08 | Michael Gladstone | Director | A | +16,250 deriv. | — |
| 2023-03-08 | Michael Gladstone | Director | MIXED | — | — |
| 2023-03-08 | David P Bonita | Director | MIXED | — | — |
| 2023-03-08 | Robert J Perez | Director | MIXED | — | — |
| 2023-03-08 | Julie Person | Chief Administrative Officer | MIXED | +119,000 deriv. | — |
| 2023-03-08 | Thomas P Soloway | Director | MIXED | — | — |
| 2023-03-08 | Mark T Iwicki | Director | MIXED | — | — |
| 2023-03-08 | Natalie C. Holles | CEO | MIXED | +360,000 deriv. | — |
| 2023-03-08 | Edward R. Conner | Chief Medical Officer | MIXED | +137,000 deriv. | — |
| Insider | Role | Shares Held | Value |
|---|---|---|---|
| Atlas Venture Fund XI, L.P. | 10%+ Owner | 9,798,075 | $52.71M |
| BIOTECHNOLOGY VALUE FUND L P | — | 1,794,218 | $9.65M |
| Natalie C. Holles | CEO | 1,218,836 | $6.56M |
| Julie Person | CHIEF ADMINISTRATIVE OFFICER | 503 | $2.71K |
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 THRD quote page; the site-wide leaderboard is on the insider transactions hub.
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.