🕵️ Newamsterdam Pharma Co N.V. ($NAMS)
SEC insider & ownership activity, last 12 months · CIK 1936258 · every row links its SEC filing
Over the last 12 months insiders sold $62.0M against $242K of open-market buying. Michael H. Davidson sold $25.3M (Jan–Sep). Capital World Investors added 8.7% → 10.4%; Frazier Life Sciences Public Fund, L.P. added 5.0% → 7.7%. No red-flag 8-Ks in the window.
Monthly net open-market insider flow, last 12 months (up = net buying)
Insider flow
2 buyers, $242K (2 lots) · 6 sellers, $62.0M (42 lots)
| Insider | Buys | Bought | Sells | Sold | Last |
|---|---|---|---|---|---|
| Michael H. Davidson | 1 | $226K | 9 | $25.3M | Sep 14, 2026 |
| Kooij Louise Frederika | 0 | – | 16 | $16.8M | Jul 20, 2026 |
| Kastelein Johannes Jacob Pieter | 0 | – | 7 | $14.3M | Aug 24, 2026 |
| Mayur Somaiya | 0 | – | 6 | $3.4M | Jan 21, 2026 |
| Louis G. Lange | 0 | – | 3 | $2.2M | Mar 11, 2026 |
| John W. Smither | 0 | – | 1 | $41K | Sep 4, 2026 |
| James N. Topper | 1 | $16K | 0 | – | Sep 15, 2025 |
5%+ holders
| Holder | Stake | Class | Schedule | Event | |
|---|---|---|---|---|---|
| Capital World Investors | 10.4% | 13G | Jun 4, 2026 | filing ↗ | |
| RA Capital Management, L.P. | 9.9% | 13G | May 15, 2025 | filing ↗ | |
| Peter Kolchinsky | 9.9% | 13G | May 15, 2025 | filing ↗ | |
| Rajeev Shah | 9.9% | 13G | May 15, 2025 | filing ↗ | |
| RA Capital Healthcare Fund, L.P. | 9.9% | 13G | May 15, 2025 | filing ↗ | |
| FMR LLC | 8.8% | 13G | Aug 6, 2026 | filing ↗ | |
| Abigail P. Johnson | 8.8% | 13G | Aug 6, 2026 | filing ↗ | |
| ForGrowth Nap B.v. | 8.3% | 13D | Sep 26, 2025 | filing ↗ | |
| Frazier Life Sciences Public Fund, L.P. | 7.7% | 13D | Nov 1, 2025 | filing ↗ | |
| Fhmlsp, L.P. | 7.7% | 13D | Nov 1, 2025 | filing ↗ | |
| Fhmlsp, L.L.C. | 7.7% | 13D | Nov 1, 2025 | filing ↗ | |
| Patrick J. Heron | 6.5% | 13D | Nov 1, 2025 | filing ↗ | |
| James N. Topper | 6.5% | 13D | Nov 1, 2025 | filing ↗ | |
| Frazier Life Sciences X, L.P. | 6.5% | 13D | Nov 1, 2025 | filing ↗ | |
| Fhmls X, L.P. | 6.5% | 13D | Nov 1, 2025 | filing ↗ | |
| Fhmls X, L.L.C. | 6.5% | 13D | Nov 1, 2025 | filing ↗ |
Planned insider sales (Form 144)
| Seller | Planned | Approx. sale date | |
|---|---|---|---|
| Kastelein Johannes Jacob Pieter | $7.0M | Aug 25, 2026 | filing ↗ |
| Louise Kooij | $7.4M | May 26, 2026 | filing ↗ |
| Louis G. Lange | $1.4M | Mar 11, 2026 | filing ↗ |
| Louis G. Lange | $879K | Mar 6, 2026 | filing ↗ |
| Kastelein Johannes Jacob Pieter | $9.4M | Mar 2, 2026 | filing ↗ |
| Michael H. Davidson | $15.7M | Mar 2, 2026 | filing ↗ |
| Michael H. Davidson | $27.1M | Feb 24, 2026 | filing ↗ |
| Kastelein Johannes Jacob Pieter | $1.6M | Feb 20, 2026 | filing ↗ |
| Mayur Somaiya | $6.3M | Jan 20, 2026 | filing ↗ |
| Michael Davidson | $411K | Jan 7, 2026 | filing ↗ |
| Douglas F. Kling | $10.0M | Jan 6, 2026 | filing ↗ |
| Louise Kooij | $88K | Jan 5, 2026 | filing ↗ |
| Johannes Kastelein | $199K | Jan 5, 2026 | filing ↗ |
| Mayur Ian Somaiya | $170K | Jan 5, 2026 | filing ↗ |
| Louise Kooij | $10.6M | Dec 23, 2025 | filing ↗ |
| BAIN Capital Life Sciences Fund II, L.P. | $10.3M | Dec 2, 2025 | filing ↗ |
| BCLS II Investco, LP | $172.5M | Dec 2, 2025 | filing ↗ |
| BCIP Life Sciences Associates, LP | $1.2M | Dec 2, 2025 | filing ↗ |
Material events (8-K)
| Item | Event date | |
|---|---|---|
| Officer/director changes (5.02) | Aug 10, 2026 | filing ↗ |
| Earnings (2.02) | Aug 5, 2026 | filing ↗ |
| Financial Statements and Exhibits (9.01) | Aug 5, 2026 | filing ↗ |
| Other events (8.01) | Jul 24, 2026 | filing ↗ |
| Financial Statements and Exhibits (9.01) | Jul 24, 2026 | filing ↗ |
| Officer/director changes (5.02) | Jul 16, 2026 | filing ↗ |
| Officer/director changes (5.02) | Jul 16, 2026 | filing ↗ |
| Officer/director changes (5.02) | Jun 2, 2026 | filing ↗ |
| Shareholder vote (5.07) | Jun 2, 2026 | filing ↗ |
| Financial Statements and Exhibits (9.01) | Jun 2, 2026 | filing ↗ |
| Earnings (2.02) | May 7, 2026 | filing ↗ |
| Financial Statements and Exhibits (9.01) | May 7, 2026 | filing ↗ |
| Officer/director changes (5.02) | Apr 20, 2026 | filing ↗ |
| Reg FD disclosure (7.01) | Mar 2, 2026 | filing ↗ |
| Financial Statements and Exhibits (9.01) | Mar 2, 2026 | filing ↗ |
| Earnings (2.02) | Feb 18, 2026 | filing ↗ |
| Financial Statements and Exhibits (9.01) | Feb 18, 2026 | filing ↗ |
| Earnings (2.02) | Jan 9, 2026 | filing ↗ |
| Reg FD disclosure (7.01) | Jan 9, 2026 | filing ↗ |
| Financial Statements and Exhibits (9.01) | Jan 9, 2026 | filing ↗ |
| Earnings (2.02) | Nov 5, 2025 | filing ↗ |
| Reg FD disclosure (7.01) | Nov 5, 2025 | filing ↗ |
| Financial Statements and Exhibits (9.01) | Nov 5, 2025 | filing ↗ |