NewAmsterdam Pharma Company N.V. NAMSW NASDAQ

NASDAQ Capital Marke • Healthcare • Biotechnology • NL • USD

NewAmsterdam Pharma Company N.V. (NAMSW) has 14 known insider and institutional holders on record. The largest holder is ForGrowth NAP B.V. with 11,831,461 shares. Other notable holders include Bain Capital Life Sciences Investors, LLC and Topper James N.

Over the last 12 months, insiders have made 39 transactions in NAMSW stock — 12 buys (valued at $12.95M) and 25 sells (valued at $39.65M). Insider selling has exceeded buying during this period.

NAMSW Insider Ownership

Top Holder

ForGrowth NAP B.V.

11,831,461 shares

Buys (12 mo)

$12.95M value

Sells (12 mo)

$39.65M value

12-Month Transaction Activity

Buy 31%

Sell 64%

Top Insider Holders

#	Name	Role	Shares Owned	Last Filed	Relative Size
1	Forgrowth Nap B.v.	10 Percent Owner	11,831,461	2024-01-02	100%
2	Bain Capital Life Sciences Investors, Llc	10 Percent Owner	10,473,913	2023-12-29	89%
3	Topper James N	Director	3,028,524	2025-09-17	26%
4	Kling Douglas F	Chief Operating Officer	323,771	2024-01-03	3%
5	Davidson Michael H.	Chief Executive Officer	174,144	2026-03-02	1%
6	Kastelein Johannes Jacob Pieter	Chief Scientific Officer	69,302	2026-03-09	1%
7	Somaiya Mayur Ian	Chief Financial Officer	58,382	2026-01-22	0%
8	Kooij Louise Frederika	Chief Accounting Officer	24,353	2026-01-29	0%
9	Gulfo Adele M.	Director	14,260	2026-01-09	0%
10	Lewis William	Director	10,360	2026-01-09	0%
11	Van Der Kamp Hilde Johanna	Director	10,360	2026-01-09	0%
12	Smither John W	Director	10,360	2026-01-09	0%
13	Lange Louis G	Director	10,360	2026-03-12	0%
14	Mckenna Mark C.	Director	10,360	2026-01-09	0%

Recent Transactions (last 12 months)

Date	Name	Role	Type	Shares	Price	Value
2026-03-11	Lange Louis G	Director	Informative Sell	446	$31.23	$13.93K
2026-03-09	Lange Louis G	Director	Option Exercise (ITM)	44,619	$11.50	$513.12K
2026-03-06	Lange Louis G	Director	Informative Sell	28,186	$29.41	$828.95K
2026-03-09	Kastelein Johannes Jacob Pieter	Chief Scientific Officer	Informative Sell	101,409	$30.29	$3.07M
2026-03-06	Kastelein Johannes Jacob Pieter	Chief Scientific Officer	Informative Sell	94,124	$30.32	$2.85M
2026-03-05	Kastelein Johannes Jacob Pieter	Chief Scientific Officer	Informative Sell	104,467	$30.30	$3.17M
2026-03-02	Davidson Michael H.	Chief Executive Officer	Informative Sell	443,707	$33.25	$14.75M
2026-02-26	Davidson Michael H.	Chief Executive Officer	Informative Sell	17,924	$34.44	$617.3K
2026-02-25	Davidson Michael H.	Chief Executive Officer	Informative Sell	1,300	$36.68	$47.68K
2026-02-24	Davidson Michael H.	Chief Executive Officer	Informative Sell	3,161	$36.46	$115.25K
2026-02-20	Kastelein Johannes Jacob Pieter	Chief Scientific Officer	Informative Sell	30,789	$35.46	$1.09M
2026-01-28	Kooij Louise Frederika	Chief Accounting Officer	Informative Sell	32,612	$31.80	$1.04M
2026-01-27	Kooij Louise Frederika	Chief Accounting Officer	Informative Sell	39,816	$32.62	$1.3M
2026-01-26	Kooij Louise Frederika	Chief Accounting Officer	Informative Sell	309	$33.45	$10.34K
2026-01-23	Kooij Louise Frederika	Chief Accounting Officer	Informative Sell	12,767	$34.37	$438.8K
2026-01-21	Somaiya Mayur Ian	Chief Financial Officer	Informative Sell	24,362	$33.80	$823.44K
2026-01-20	Somaiya Mayur Ian	Chief Financial Officer	Informative Sell	19,604	$32.38	$634.78K
2026-01-07	Van Der Kamp Hilde Johanna	Director	RSU Award	3,400	-	-
2026-01-07	Mckenna Mark C.	Director	RSU Award	3,400	-	-
2026-01-07	Gulfo Adele M.	Director	RSU Award	3,400	-	-
2026-01-07	Davidson Michael H.	Chief Executive Officer	RSU Award	364,000	$35.45	$12.9M
2026-01-07	Smither John W	Director	RSU Award	3,400	-	-
2026-01-07	Lewis William	Director	RSU Award	3,400	-	-
2026-01-07	Lange Louis G	Director	RSU Award	3,400	-	-
2026-01-07	Kooij Louise Frederika	Chief Accounting Officer	RSU Award	12,000	-	-