According to recent filings covering the 90 days ending January 13, 2026, the three most significant insider holders at Prime Medicine are TenPercentOwner David R. Liu (20.24Mn shares), TenPercentOwner Venture Partners Xii, Llc Arch (6.13Mn shares), TenPercentOwner Venture Partners X, Llc Arch (6.13Mn shares).
| Holder | Position | Shares | Report Date |
|---|---|---|---|
| David R. Liu | 20,240,945 | 01 Jul, 2025 | |
| Robert Nelsen | 6,128,297 | 01 Aug, 2025 | |
| Venture Partners X, Llc Arch | 6,128,297 | 01 Aug, 2025 | |
| Venture Partners Xii, Llc Arch | 6,128,297 | 01 Aug, 2025 | |
| Thomas Cahill | 5,305,679 | 26 Oct, 2022 | |
| Llc Fmr | 4,228,589 | 26 Oct, 2022 | |
| 2021 Gp, L.L.C. Gv | 3,262,440 | 05 Aug, 2025 | |
| Keith Michael Gottesdiener | Nan | 2,993,096 | 07 Jun, 2024 |
| Allan Reine | Chief Executive Officer | 125,000 | 22 May, 2025 |
| Ann L. Lee | Chief Technical Officer | 100,000 | 22 May, 2025 |
| Richard Brudnick | Chief Business Officer | 20,000 | 22 May, 2025 |
* Please note that the shares above only reflect shares from the fund portfolio and the institutional portfolio. Shares from the personal portfolio are excluded from this Institutional Ownership Page. See these insiders' latest transactions here on Insider Page.
| Transaction Date | Insider Name | Security Class | Transaction Type | Shares Traded | Price | Shares Remaining | Ownership | Code |
|---|---|---|---|---|---|---|---|---|
| 01 Aug, 2025 | Robert Nelsen | Common Stock | A | 3,030,300 | $3.30 | 6,128,297 | I | P |
| 01 Aug, 2025 | Venture Partners X, Llc Arch | Common Stock | A | 3,030,300 | $3.30 | 6,128,297 | I | P |
| 01 Aug, 2025 | 2021 Gp, L.L.C. Gv | Common Stock | A | 1,500,000 | $3.30 | 3,262,440 | I | P |
| 01 Aug, 2025 | Venture Partners Xii, Llc Arch | Common Stock | A | 3,030,300 | $3.30 | 6,128,297 | I | P |
| 30 Jun, 2025 | David R. Liu | Common Stock | A | 21,000 | $2.52 | 20,240,945 | D | P |
| 23 Jun, 2025 | David R. Liu | Common Stock | A | 21,000 | $2.16 | 20,219,945 | D | P |
| 16 Jun, 2025 | David R. Liu | Common Stock | A | 21,000 | $1.49 | 20,198,945 | D | P |
| 11 Jun, 2025 | David R. Liu | Common Stock | A | 21,000 | $1.60 | 20,177,945 | D | P |
| 11 Jun, 2025 | David R. Liu | - | - | 20,177,945 | D | |||
| 21 May, 2025 | Allan Reine | Common Stock | A | 125,000 | $1.18 | 125,000 | D | P |
| 21 May, 2025 | Ann L. Lee | Common Stock | A | 100,000 | $1.13 | 100,000 | D | P |
| 21 May, 2025 | Ann L. Lee | - | - | 100,000 | D | |||
| 20 May, 2025 | Richard Brudnick | - | - | 20,000 | D | |||
| 20 May, 2025 | Richard Brudnick | Common Stock | A | 20,000 | $1.19 | 20,000 | D | P |
| 08 Oct, 2024 | Keith Michael Gottesdiener | Common Stock | A | 226,925 | $0.00 | 682,259 | I | G |
| 08 Oct, 2024 | Keith Michael Gottesdiener | Common Stock | D | 226,925 | $0.00 | 50,241 | I | G |
| 08 Oct, 2024 | Keith Michael Gottesdiener | - | - | 50,241 | I | |||
| 08 Oct, 2024 | Keith Michael Gottesdiener | - | - | 682,259 | I | |||
| 05 Jun, 2024 | Keith Michael Gottesdiener | Common Stock | D | 250,000 | $0.00 | 2,310,837 | D | G |
| 05 Jun, 2024 | Keith Michael Gottesdiener | - | - | 2,310,837 | D |