Dudediligence.

NewAmsterdam Pharma Company N.V.

NAMSNASDAQ · Pharmaceutical Preparations
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Last 12 months

Sales planned on beside the trades reported on , and whether each names a .

Planned ·

$282.3M

18 notices · 7,687,340 sh

Oct 2025 to Oct 2026

Reported ·

$55.4M

37 sales · 0 buys

Oct 2025 to Jun 2026

The two figures cover different periods.

31 of 37 reported sales carry the 10b5-1 box. Together they are 1.41% of the shares on issue.

PLANNED · FORM 144Oct 2025 to Oct 2026REPORTED · FORM 4Oct 2025 to Jun 2026N2025DJ2026FMAMJJASO2026-08-25: Kastelein Johannes Jacob Pieter, Form 1442026-05-26: Louise Kooij, Form 1442026-03-11: Louis G. Lange, Form 1442026-03-06: Louis G. Lange, Form 1442026-03-02: Kastelein Johannes Jacob Pieter, Form 1442026-03-02: Michael H. Davidson, Form 1442026-02-24: Michael H. Davidson, Form 1442026-02-20: Kastelein Johannes Jacob Pieter, Form 1442026-01-20: Mayur Somaiya, Form 1442026-01-07: Michael Davidson, Form 1442026-01-06: Douglas F Kling, Form 1442026-01-05: Louise Kooij, Form 1442026-01-05: Johannes Kastelein, Form 1442026-01-05: Mayur Ian Somaiya, Form 1442025-12-23: Louise Kooij, Form 1442025-12-02: Bain Capital Life Sciences Fund II, L.P., Form 1442025-12-02: BCLS II Investco, LP, Form 1442025-12-02: BCIP Life Sciences Associates, LP, Form 1442025-12-23: Kooij Louise Frederika, sold2026-01-05: Somaiya Mayur Ian, sold2026-01-05: Kooij Louise Frederika, sold2026-01-05: Kastelein Johannes Jacob Pieter, sold2026-01-07: Davidson Michael H., sold2026-01-20: Somaiya Mayur Ian, sold2026-01-23: Kooij Louise Frederika, sold2026-01-27: Kooij Louise Frederika, sold2026-02-20: Kastelein Johannes Jacob Pieter, sold2026-02-24: Davidson Michael H., sold2026-03-02: Davidson Michael H., sold2026-03-05: Kastelein Johannes Jacob Pieter, sold2026-03-06: LANGE LOUIS G, sold2026-03-11: LANGE LOUIS G, sold2026-05-26: Kooij Louise Frederika, sold2026-06-22: Kooij Louise Frederika, sold
under a no plan named▼ salesize is dollars

Form 144 notices, newest first

2026-08-25Kastelein Johannes Jacob Pieter, Chief Scientific Officer$6,967,500
250,000 shplan 2026-03-31Form 4s on file end Jun 23144 ↗
2026-05-26Louise Kooij, Chief Accounting Officer$7,442,400
210,000 shplan 2026-02-23144 ↗
Form 4, 2026-05-27: sold 65,000 at $35.69 Form 4 ↗
2026-03-11Louis G. Lange, Affiliate$1,395,236
44,619 shno plan date144 ↗
Form 4, 2026-03-12: sold 44,619 at $30.42 Form 4 ↗
2026-03-06Louis G. Lange, Affiliate$878,839
28,186 shplan 2025-12-04144 ↗
Form 4, 2026-03-10: sold 28,186 at $29.41 Form 4 ↗
2026-03-02Kastelein Johannes Jacob Pieter, Chief Scientific Officer$9,354,000
300,000 shplan 2025-12-04144 ↗
Form 4, 2026-03-09: sold 300,000 at $30.30 Form 4 ↗
2026-03-02Michael H. Davidson, Chief Executive Officer$15.7M
443,707 shno plan date144 ↗
Form 4, 2026-03-02: sold 443,707 at $33.25 Form 4 ↗
2026-02-24Michael H. Davidson, Chief Executive Officer$27.1M
750,000 shplan 2025-09-29144 ↗
Form 4, 2026-02-26: sold 306,293 at $34.53 Form 4 ↗
2026-02-20Kastelein Johannes Jacob Pieter, Chief Scientific Officer$1,575,007
45,481 shno plan date144 ↗
Form 4, 2026-02-24: sold 45,481 at $35.31 Form 4 ↗
2026-01-20Mayur Somaiya, Chief Financial Officer$6,330,000
200,000 shplan 2025-09-30144 ↗
Form 4, 2026-01-22: sold 100,000 at $32.61 Form 4 ↗
2026-01-07Michael Davidson, Chief Executive Officer$410,889
11,582 sh10b5-1 plan144 ↗
Form 4, 2026-01-09: sold 11,582 Form 4 ↗
2026-01-06Douglas F Kling, Chief Operating Officer$10.0M
300,000 shplan 2025-09-29no Form 4 on file144 ↗
2026-01-05Louise Kooij, Chief Accounting Officer$88,012
2,647 sh10b5-1 plan144 ↗
Form 4, 2026-01-07: sold 2,647 at $33.25 Form 4 ↗
2026-01-05Johannes Kastelein, Chief Scientific Officer$199,499
6,000 sh10b5-1 plan144 ↗
Form 4, 2026-01-07: sold 6,000 at $33.25 Form 4 ↗
2026-01-05Mayur Ian Somaiya, Chief Financial Officer$170,173
5,118 sh10b5-1 plan144 ↗
Form 4, 2026-01-07: sold 5,118 at $33.25 Form 4 ↗
2025-12-23Louise Kooij, Chief Accounting Officer$10.6M
290,000 shplan 2025-09-23144 ↗
Form 4, 2025-12-29: sold 145,000 at $35.84 Form 4 ↗
2025-12-02Bain Capital Life Sciences Fund II, L.P., Former Affiliate$10.3M
267,429 shno plan dateno Form 4 on file144 ↗
2025-12-02BCLS II Investco, LP, Former Affiliate$172.5M
4,500,000 shno plan dateno Form 4 on file144 ↗
2025-12-02BCIP Life Sciences Associates, LP, Former Affiliate$1,248,446
32,571 shno plan dateno Form 4 on file144 ↗