NewAmsterdam Pharma Company N.V. (NAMS) Insider Trading
Over the last 3 months, NAMS insiders made 0 open-market buys and 6 sales, a net sale of -$7.8M (SEC Form 4). Over the last 6 months, 141 institutions increased and 103 reduced their position (13F).
Insider Activity
Sentiment
0/100
Buys (3m)
0
Sells (3m)
6
Net (3m)
-$7.8M
Insider trades by month Buys Sells
Feb
Mar
May
Jun
Jul
Aug
Context3-month price -21.1%Institutions accumulating (13F)
| Date | Insider | Type | Shares | Price |
|---|---|---|---|---|
| Aug 25, 2026 | Kastelein Johannes Jacob Pieterdirector, officer: Chief Scientific Officer | Sell | 125,000 | $26.91 |
| Aug 25, 2026 | Kastelein Johannes Jacob Pieterdirector, officer: Chief Scientific Officer | Option | 125,000 | — |
| Jul 22, 2026 | Kooij Louise Frederikaofficer: Chief Accounting Officer | Sell | 2,915 | $31.71 |
| Jul 22, 2026 | Kooij Louise Frederikaofficer: Chief Accounting Officer | Option | 25,000 | $11.90 |
| Jul 22, 2026 | Kooij Louise Frederikaofficer: Chief Accounting Officer | Option | 80,000 | $11.17 |
| Jul 22, 2026 | Kooij Louise Frederikaofficer: Chief Accounting Officer | Sell | 70,200 | $29.96 |
| Jul 22, 2026 | Kooij Louise Frederikaofficer: Chief Accounting Officer | Sell | 31,885 | $31.05 |
| Jun 24, 2026 | Kooij Louise Frederikaofficer: Chief Accounting Officer | Option | 15,000 | $11.90 |
| Jun 24, 2026 | Kooij Louise Frederikaofficer: Chief Accounting Officer | Sell | 39,700 | $30.20 |
| Jun 24, 2026 | Kooij Louise Frederikaofficer: Chief Accounting Officer | Sell | 300 | $30.73 |
| Jun 24, 2026 | Kooij Louise Frederikaofficer: Chief Accounting Officer | Option | 25,000 | $10.90 |
| May 27, 2026 | Kooij Louise Frederikaofficer: Chief Accounting Officer | Sell | 65,000 | $35.69 |
| May 27, 2026 | Kooij Louise Frederikaofficer: Chief Accounting Officer | Option | 60,000 | $10.00 |
| May 27, 2026 | Kooij Louise Frederikaofficer: Chief Accounting Officer | Option | 5,000 | $10.90 |
| Mar 12, 2026 | LANGE LOUIS Gdirector | Sell | 446 | $31.23 |
| Mar 12, 2026 | LANGE LOUIS Gdirector | Sell | 44,173 | $30.41 |
| Mar 10, 2026 | LANGE LOUIS Gdirector | Sell | 28,186 | $29.41 |
| Mar 9, 2026 | Kastelein Johannes Jacob Pieterdirector, officer: Chief Scientific Officer | Sell | 101,409 | $30.29 |
| Mar 9, 2026 | Kastelein Johannes Jacob Pieterdirector, officer: Chief Scientific Officer | Option | 104,467 | — |
| Mar 9, 2026 | Kastelein Johannes Jacob Pieterdirector, officer: Chief Scientific Officer | Option | 94,124 | — |
| Mar 9, 2026 | Kastelein Johannes Jacob Pieterdirector, officer: Chief Scientific Officer | Sell | 104,467 | $30.30 |
| Mar 9, 2026 | Kastelein Johannes Jacob Pieterdirector, officer: Chief Scientific Officer | Sell | 94,124 | $30.32 |
| Mar 9, 2026 | Kastelein Johannes Jacob Pieterdirector, officer: Chief Scientific Officer | Option | 101,409 | — |
| Mar 2, 2026 | Davidson Michael H.director, officer: Chief Executive Officer | Option | 443,707 | — |
| Mar 2, 2026 | Davidson Michael H.director, officer: Chief Executive Officer | Sell | 443,707 | $33.25 |
| Feb 26, 2026 | Davidson Michael H.director, officer: Chief Executive Officer | Option | 64,708 | — |
| Feb 26, 2026 | Davidson Michael H.director, officer: Chief Executive Officer | Sell | 17,924 | $34.44 |
| Feb 26, 2026 | Davidson Michael H.director, officer: Chief Executive Officer | Sell | 165,408 | $33.63 |
| Feb 26, 2026 | Davidson Michael H.director, officer: Chief Executive Officer | Option | 183,332 | — |
| Feb 26, 2026 | Davidson Michael H.director, officer: Chief Executive Officer | Sell | 1,300 | $36.68 |
Source: NAMS SEC Form 4 filings, latest Aug 25, 2026. For informational purposes only — not investment advice.
Institutional activity (13F)
How institutions changed their NAMS positions over the last 6 months (SEC Form 13F).
Increased
141
New positions
74
Reduced
103
Sold out
22
Largest moves
| Institution | Action | Shares | Filed |
|---|---|---|---|
| Frazier Life Sciences Management, L.P. | Increased | 18.1M | Aug 14, 2026 |
| FRAZIER LIFE SCIENCES MANAGEMENT, L.P. | Unchanged | 16.9M | May 15, 2026 |
| Capital World Investors | Increased | 12.2M | Aug 12, 2026 |
| CAPITAL WORLD INVESTORS | Increased | 11.1M | May 13, 2026 |
| FMR LLC | Increased | 10.3M | Aug 13, 2026 |
| RA CAPITAL MANAGEMENT, L.P. | Unchanged | 9.6M | May 15, 2026 |
| RA CAPITAL MANAGEMENT, L.P. | Unchanged | 9.6M | Aug 14, 2026 |
| FCPM III SERVICES B.V. | Unchanged | 9.2M | May 15, 2026 |
| FMR LLC | Increased | 8.8M | May 15, 2026 |
| FCPM III SERVICES B.V. | Reduced | 8.5M | Aug 14, 2026 |
| BAIN CAPITAL LIFE SCIENCES INVESTORS, LLC | Unchanged | 7.3M | May 15, 2026 |
| WELLINGTON MANAGEMENT GROUP LLP | Increased | 5.1M | May 15, 2026 |
| DEERFIELD MANAGEMENT COMPANY, L.P. (SERIES C) | Increased | 4.3M | May 15, 2026 |
| DEERFIELD MANAGEMENT COMPANY, L.P. | Unchanged | 4.3M | Aug 14, 2026 |
| VIKING GLOBAL INVESTORS LP | Unchanged | 4.2M | May 15, 2026 |
Source: SEC Form 13F filings. For informational purposes only — not investment advice.