Based on data from the past 90 days ending December 12, 2025, NewAmsterdam Pharma Co N.V's three largest insider shareholders are Director James N Topper (3.03Mn shares), Officer Michael F Iii Marino (55.00K shares), Chief Operating Officer Douglas F Kling (44.00K 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 | 148,783 | 28 Mar, 2025 |
| Michael F Iii Marino | 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 | |
| Mayur Ian Somaiya | Chief Financial Officer | 38,000 | 29 Jan, 2025 |
| Juliette Berangere Audet | Chief Business Officer | 15,104 | 07 Jan, 2025 |
| Louise Frederika Kooij | Chief Accounting Officer | 15,000 | 10 Sep, 2025 |
| Adele M. Gulfo | 10,860 | 17 Apr, 2025 | |
| William Lewis | 6,960 | 08 Jan, 2025 | |
| Mark C. Mckenna | 6,960 | 08 Jan, 2025 | |
| Der Kamp Hilde Johanna Van | 6,960 | 08 Jan, 2025 | |
| John W Smither | 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 |
|---|---|---|---|---|---|---|---|---|
| 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 | A | 150,000 | $10.00 | 165,000 | D | M |
| 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 | 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 |
| 25 Aug, 2025 | Louise Frederika Kooij | Ordinary Shares | D | 8,269 | $24.86 | 15,000 | D | S |
| 21 Aug, 2025 | Johannes Jacob Pieter Kastelein | Ordinary Shares | D | 50,000 | $24.29 | 119,302 | I | S |
| 22 Aug, 2025 | Johannes Jacob Pieter Kastelein | Ordinary Shares | D | 42,342 | $25.08 | 76,960 | I | S |
| 22 Aug, 2025 | Johannes Jacob Pieter Kastelein | Ordinary Shares | D | 7,658 | $25.49 | 69,302 | I | S |
| 11 Aug, 2025 | James N Topper | Ordinary Shares | A | 471 | $23.98 | 3,026,604 | I | P |
| 15 Jul, 2025 | Douglas F Kling | Ordinary Shares | A | 47,569 | $10.90 | 91,569 | D | M |
| 15 Jul, 2025 | Douglas F Kling | Ordinary Shares | D | 44,025 | $21.38 | 47,544 | D | S |
| 15 Jul, 2025 | Douglas F Kling | Ordinary Shares | D | 3,544 | $22.12 | 44,000 | D | S |
| 16 Jul, 2025 | Douglas F Kling | Ordinary Shares | A | 51,043 | $10.90 | 95,043 | D | M |
| 16 Jul, 2025 | Douglas F Kling | Ordinary Shares | D | 51,043 | $21.10 | 44,000 | D | S |
| 24 Jun, 2025 | James N Topper | Ordinary Shares | A | 2,520 | $18.43 | 3,024,873 | I | P |
| 25 Jun, 2025 | James N Topper | Ordinary Shares | A | 1,260 | $18.26 | 3,026,133 | I | P |
| 16 Jun, 2025 | James N Topper | Ordinary Shares | A | 8,584 | $19.50 | 3,022,153 | I | P |