NewAmsterdam Pharma Co N.V.
NAMSW- Exchange
- Nasdaq
- Industry
- Pharmaceutical Preparations
- SEC CIK
- 0001936258
In the last 90 days, NewAmsterdam Pharma Co N.V. insiders filed 1 open-market purchase and 3 sales; 9 institutions reported holding it in 13F filings for Q2 2026, worth $28.1M in total; no superinvestor holds it.
Other share classesNAMS
Holders of 5% or more of NAMSW
Holders whose latest Schedule 13D or 13G filing reports 5% or more of NewAmsterdam Pharma Co N.V., largest stake first. The change is against the holder's previous filing.
No holder currently reports owning 5% or more of NewAmsterdam Pharma Co N.V. on Schedule 13D or 13G.
Stakes are as of each holder's latest filing. Holders whose last filing was in the old format (before December 18, 2024) have no stake on record and are not listed, and after an acquisition or delisting holders usually stop filing.
13D and 13G filings
Schedule 13D and 13G filings on NewAmsterdam Pharma Co N.V., newest first.
No Schedule 13D or 13G filings on NewAmsterdam Pharma Co N.V. are on file.
Form 144: proposed insider sales
35 notices from officers, directors and other affiliates planning to sell NewAmsterdam Pharma Co N.V. shares, newest first.
| Filed (ET) | Seller | Shares to sell | Market value | Planned sale | Broker | Filing |
|---|---|---|---|---|---|---|
| Aug 25, 20264:47 PM ETAmended | Kastelein Johannes Jacob PieterAffiliate | 250.0K | $6.97M | Aug 25, 202610b5-1 | J.P. Morgan Securities LLC | SEC |
| May 26, 20265:04 PM ET | Louise KooijOfficer | 210.0K | $7.44M | May 26, 202610b5-1 | J.P. Morgan Securities LLC | SEC |
| Mar 11, 20264:08 PM ET | Louis G. LangeAffiliate | 44.6K | $1.40M | Mar 11, 2026 | J.P. Morgan Securities LLC | SEC |
| Mar 6, 20265:52 PM ET | Louis G. LangeAffiliate | 28.2K | $878.8K | Mar 6, 202610b5-1 | J.P. Morgan Securities LLC | SEC |
| Mar 5, 20264:14 PM ET | Kastelein Johannes Jacob PieterAffiliate | 300.0K | $9.35M | Mar 2, 202610b5-1 | J.P. Morgan Securities LLC | SEC |
| Mar 2, 20264:10 PM ET | Michael H. DavidsonAffiliate | 443.7K | $15.7M | Mar 2, 2026 | J.P. Morgan Securities LLC | SEC |
| Feb 24, 20264:22 PM ET | Michael H. DavidsonAffiliate | 750.0K | $27.1M | Feb 24, 202610b5-1 | J.P. Morgan Securities LLC | SEC |
| Feb 20, 20267:51 AM ET | Kastelein Johannes Jacob PieterOfficer · Director | 45.5K | $1.58M | Feb 20, 2026 | ABN AMRO | SEC |
| Jan 20, 20264:17 PM ET | Mayur SomaiyaAffiliate | 200.0K | $6.33M | Jan 20, 202610b5-1 | J.P. Morgan Securities LLC | SEC |
| Jan 7, 20261:19 PM ET | Michael DavidsonAffiliate | 11.6K | $410.9K | Jan 7, 2026 | J.P. Morgan Securities LLC | SEC |
| Jan 6, 20264:29 PM ET | Douglas F KlingAffiliate | 300.0K | $10.0M | Jan 6, 202610b5-1 | J.P. Morgan Securities LLC | SEC |
| Jan 5, 20263:18 PM ET | Louise KooijAffiliate | 2.65K | $88.0K | Jan 5, 2026 | J.P. Morgan Securities LLC | SEC |
| Jan 5, 20263:04 PM ET | Johannes KasteleinAffiliate | 6.00K | $199.5K | Jan 5, 2026 | J.P. Morgan Securities LLC | SEC |
| Jan 5, 20263:03 PM ET | Mayur Ian SomaiyaAffiliate | 5.12K | $170.2K | Jan 5, 2026 | J.P. Morgan Securities LLC | SEC |
| Dec 23, 20255:31 PM ET | Louise KooijOfficer | 290.0K | $10.6M | Dec 23, 202510b5-1 | J.P. Morgan Securities LLC | SEC |
| Dec 2, 20259:25 PM ET | Bain Capital Life Sciences Fund II, L.P.Former affiliate | 267.4K | $10.3M | Dec 2, 2025 | Goldman Sachs & Co. LLC | SEC |
| Dec 2, 20259:23 PM ET | BCLS II Investco, LPFormer affiliate | 4.50M | $172.5M | Dec 2, 2025 | Goldman Sachs & Co. LLC | SEC |
| Dec 2, 20259:22 PM ET | BCIP Life Sciences Associates, LPFormer affiliate | 32.6K | $1.25M | Dec 2, 2025 | Goldman Sachs & Co. LLC | SEC |
| Sep 9, 202511:57 AM ET | Louise KooijAffiliate | 150.0K | $3.78M | Sep 9, 2025 | J.P. Morgan Securities LLC | SEC |
| Sep 3, 20258:21 AM ET | Kooij Louise FrederikaOfficer | 18.1K | $434.7K | Sep 3, 2025 | Cooperatieve Rabobank U.A. | SEC |
| Aug 27, 20254:57 PM ET | Kooij Louise FrederikaOfficer | 8.27K | $208.3K | Aug 25, 2025 | Cooperatieve Rabobank U.A. | SEC |
| Aug 25, 20255:03 PM ET | Kastelein Johannes Jacob PieterOfficer · Director | 100.0K | $2.50M | Aug 21, 2025 | ABN AMRO | SEC |
| Jul 14, 20254:12 PM ET | NAP PoolCo B.V.Affiliate | 1.43M | $30.9M | Jul 14, 202510b5-1 | UBS Financial Services Inc. | SEC |
| Jun 18, 202512:31 PM ET | NAP PoolCo B.V.Affiliate | 303.2K | $5.91M | Jun 16, 2025 | Van Lanschot Kempen N.V. | SEC |
| May 15, 20254:40 PM ET | Douglas F KlingAffiliate | 298.6K | $5.60M | May 15, 202510b5-1 | J.P. Morgan Securities LLC | SEC |
Showing the latest 25. See the NAMSW notices from the last 12 months