Based on data from the past 90 days ending January 09, 2026, NewAmsterdam Pharma Co N.V's three largest insider shareholders are TenPercentOwner Nap B.V. Forgrowth (10.66Mn shares), Director James N Topper (3.03Mn shares), Chief Executive Officer Michael H. Davidson (390.44K shares).
| Holder | Position | Shares | Report Date |
|---|---|---|---|
| Nap B.V. Forgrowth | 10,656,172 | 02 Jan, 2025 | |
| James N Topper | 3,028,524 | 17 Sep, 2025 | |
| Michael H. Davidson | Chief Executive Officer | 390,441 | 28 Mar, 2025 |
| Johannes Jacob Pieter Kastelein | Chief Scientific Officer | 168,283 | 07 Jan, 2026 |
| Mayur Ian Somaiya | Chief Financial Officer | 58,382 | 07 Jan, 2026 |
| Michael F Iii Marino | Nan | 55,000 | 03 Jun, 2025 |
| Douglas F Kling | Chief Operating Officer | 44,000 | 17 Jul, 2025 |
| William A Jr Jones | Chief Commercial Officer | 43,000 | 07 Jan, 2025 |
| Louis G Lange | 38,248 | 28 Mar, 2025 | |
| Louise Frederika Kooij | Chief Accounting Officer | 24,353 | 07 Jan, 2026 |
| Juliette Berangere Audet | Chief Business Officer | 15,104 | 07 Jan, 2025 |
| Adele M. Gulfo | 10,860 | 17 Apr, 2025 | |
| William Lewis | 6,960 | 08 Jan, 2025 | |
| Der Kamp Hilde Johanna Van | 6,960 | 08 Jan, 2025 | |
| John W Smither | 6,960 | 08 Jan, 2025 | |
| Mark C. Mckenna | 6,960 | 08 Jan, 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 |
|---|---|---|---|---|---|---|---|---|
| 07 Jan, 2026 | Mayur Ian Somaiya | Ordinary Shares | A | 25,500 | - | 58,382 | D | A |
| 07 Jan, 2026 | Johannes Jacob Pieter Kastelein | Ordinary Shares | A | 25,500 | - | 98,981 | D | A |
| 07 Jan, 2026 | Louise Frederika Kooij | Ordinary Shares | A | 12,000 | - | 24,353 | D | A |
| 05 Jan, 2026 | Mayur Ian Somaiya | Ordinary Shares | D | 5,118 | $33.25 | 32,882 | D | S |
| 05 Jan, 2026 | Johannes Jacob Pieter Kastelein | Ordinary Shares | D | 6,000 | $33.25 | 73,481 | D | S |
| 05 Jan, 2026 | Louise Frederika Kooij | Ordinary Shares | D | 2,647 | $33.25 | 12,353 | D | S |
| 26 Dec, 2025 | Louise Frederika Kooij | Ordinary Shares | A | 38,872 | $10.00 | 53,872 | D | M |
| 26 Dec, 2025 | Louise Frederika Kooij | Ordinary Shares | A | 5,000 | $10.90 | 58,872 | D | M |
| 26 Dec, 2025 | Louise Frederika Kooij | Ordinary Shares | D | 43,872 | $35.30 | 15,000 | D | S |
| 24 Dec, 2025 | Louise Frederika Kooij | Ordinary Shares | D | 26,011 | $35.68 | 15,000 | D | S |
| 24 Dec, 2025 | Louise Frederika Kooij | Ordinary Shares | A | 26,011 | $10.00 | 41,011 | D | M |
| 23 Dec, 2025 | Louise Frederika Kooij | Ordinary Shares | A | 75,117 | $10.00 | 90,117 | D | M |
| 23 Dec, 2025 | Louise Frederika Kooij | Ordinary Shares | D | 75,117 | $36.21 | 15,000 | D | S |
| 15 Sep, 2025 | James N Topper | Ordinary Shares | A | 660 | $23.70 | 3,028,524 | I | P |
| 09 Sep, 2025 | Louise Frederika Kooij | Ordinary Shares | D | 53,104 | $25.31 | 111,896 | D | S |
| 09 Sep, 2025 | Louise Frederika Kooij | Ordinary Shares | A | 150,000 | $10.00 | 165,000 | D | M |
| 09 Sep, 2025 | Louise Frederika Kooij | Ordinary Shares | D | 96,896 | $26.11 | 15,000 | D | S |
| 08 Sep, 2025 | James N Topper | Ordinary Shares | A | 1,260 | $24.99 | 3,027,864 | I | P |
| 03 Sep, 2025 | Louise Frederika Kooij | Ordinary Shares | D | 18,073 | $25.09 | 15,000 | D | S |
| 02 Sep, 2025 | Louise Frederika Kooij | Ordinary Shares | A | 18,073 | - | 33,073 | D | M |