Kastelein Johannes Jacob Pieter
- SEC CIK
- 0002000389
In the past year, 4 open-market sale filings worth $14.3M and no purchases.
Current role at each company
- NAMS NewAmsterdam Pharma Co N.V.Chief Scientific Officeras of Aug 25, 2026
Open-market trades in the past year
Open-market purchases (P) and sales (S) filed in the last 365 days, not counting derivative securities or duplicate filings. Values leave out price outliers.
- Bought
- –
- 0 filings
- Sold
- $14.3M
- 4 filings
- Net
- −$14.3M
- Bought minus sold
- Companies
- 1
- With open-market trades
Trades
Every Form 4 that lists Kastelein Johannes Jacob Pieter as a reporting owner, including filings made jointly with others, grouped by company. Each row adds up one type of transaction in one filing. Only open-market purchases (P) and sales (S) are shown by default.
| Filed (ET) | Trade date | Filing delay | Insider | Transaction | Shares | Avg price | Value | Holding change | Flags |
|---|---|---|---|---|---|---|---|---|---|
| Aug 25, 2026 (view filing)4:30 PM ET | Aug 24 | 1 day | Kastelein Johannes Jacob PieterChief Scientific Officer | SSale | −125.0K | $26.91 | −$3.36M | −64.3%69.3K after | 10b5-1 |
| Mar 9, 2026 (view filing) | Mar 5-9 | 4 days | Kastelein Johannes Jacob PieterChief Scientific Officer | SSale | −300.0K | $30.30 | −$9.09M | −81.2%69.3K after | 3 lots10b5-1 |
| Feb 24, 2026 (view filing) | Feb 20 | 4 days | Kastelein Johannes Jacob PieterChief Scientific Officer | SSale | −45.5K | $35.31 | −$1.61M | −45.9%53.5K after | 2 lots |
| Jan 7, 2026 (view filing) | Jan 5 | 2 days | Kastelein Johannes Jacob PieterChief Scientific Officer | SSale | −6.00K | $33.25 | −$199.5K | −7.5%73.5K after | 10b5-1 |
| Aug 25, 2025 (view filing) | Aug 21-22 | 4 days | Kastelein Johannes Jacob PieterChief Scientific Officer | SSale | −100.0K | $24.72 | −$2.47M | −59.1%69.3K after | 3 lots |
| Mar 27, 2024 (view filing) | Mar 26 | 1 day | Kastelein Johannes Jacob PieterChief Scientific Officer | SSale | −190.5K | $21.50 | −$4.10M | −100.0%0 after |