NewAmsterdam Pharma Company N.V. (NAMS) has 17 known insider and institutional holders on record. The largest holder is ForGrowth NAP B.V. with 10,656,172 shares. Other notable holders include Topper James N and Bain Capital Life Sciences Investors, LLC.
Over the last 12 months, insiders have made 53 transactions in NAMS stock — 18 buys (valued at $13.79M) and 28 sells (valued at $41.86M). Insider selling has exceeded buying during this period.
NAMS Insider Ownership
Top Holder
ForGrowth NAP B.V.
10,656,172 shares
Buys (12 mo)
18
$13.79M value
Sells (12 mo)
28
$41.86M value
12-Month Transaction Activity
Top Insider Holders
| # |
Name |
Role |
Shares Owned |
Last Filed |
Relative Size |
| 1 |
Forgrowth Nap B.v. |
10 Percent Owner |
10,656,172 |
2025-01-02 |
|
| 2 |
Topper James N |
Director |
3,028,524 |
2025-09-17 |
|
| 3 |
Bain Capital Life Sciences Investors, Llc |
10 Percent Owner |
1,632,653 |
2024-12-17 |
|
| 4 |
Davidson Michael H. |
Chief Executive Officer |
174,144 |
2026-03-02 |
|
| 5 |
Kastelein Johannes Jacob Pieter |
Chief Scientific Officer |
69,302 |
2026-03-09 |
|
| 6 |
Somaiya Mayur Ian |
Chief Financial Officer |
58,382 |
2026-01-22 |
|
| 7 |
Marino Michael F Iii |
See Remarks |
55,000 |
2025-06-03 |
|
| 8 |
Kling Douglas F |
Chief Operating Officer |
44,000 |
2025-06-18 |
|
| 9 |
Jones William A Jr |
Chief Commercial Officer |
43,000 |
2025-01-07 |
|
| 10 |
Audet Juliette Berangere |
See Remarks |
30,000 |
2025-05-02 |
|
| 11 |
Kooij Louise Frederika |
Chief Accounting Officer |
24,353 |
2026-01-29 |
|
| 12 |
Gulfo Adele M. |
Director |
14,260 |
2026-01-09 |
|
| 13 |
Lange Louis G |
Director |
10,360 |
2026-03-12 |
|
| 14 |
Van Der Kamp Hilde Johanna |
Director |
10,360 |
2026-01-09 |
|
| 15 |
Smither John W |
Director |
10,360 |
2026-01-09 |
|
| 16 |
Lewis William |
Director |
10,360 |
2026-01-09 |
|
| 17 |
Mckenna Mark C. |
Director |
10,360 |
2026-01-09 |
|
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 |
- |
- |