Updated Jul 16, 2026
Kastelein Johannes Jacob Pieter is a corporate insider tracked by InsiderAlpha. No SEC Form 4 filings recorded in the last 90 days. Lifetime open-market sales: $13.37M.
| Date | Ticker | Company | Code | Shares | Price | Value |
|---|---|---|---|---|---|---|
| 2026-03-10 | NAMS | NewAmsterdam Pharma Co N.V. | S — Open-market sale | 101.4K | $30.29 | $3.07M |
| 2026-03-10 | NAMS | NewAmsterdam Pharma Co N.V. | M — Option exercise | 101.4K | — | |
| 2026-03-10 | NAMS | NewAmsterdam Pharma Co N.V. | S — Open-market sale | 94.1K | $30.32 | $2.85M |
| 2026-03-10 | NAMS | NewAmsterdam Pharma Co N.V. | M — Option exercise | 94.1K | — | |
| 2026-03-10 | NAMS | NewAmsterdam Pharma Co N.V. | S — Open-market sale | 104.5K | $30.30 | $3.17M |
| 2026-03-10 | NAMS | NewAmsterdam Pharma Co N.V. | M — Option exercise | 104.5K | — | |
| 2026-02-24 | NAMS | NewAmsterdam Pharma Co N.V. | S — Open-market sale | 30.8K | $35.46 | $1.09M |
| 2026-02-24 | NAMS | NewAmsterdam Pharma Co N.V. | S — Open-market sale | 14.7K | $35.00 | $514K |
| 2026-01-07 | NAMS | NewAmsterdam Pharma Co N.V. | A — Grant or award | 25.5K | — | |
| 2026-01-07 | NAMS | NewAmsterdam Pharma Co N.V. | S — Open-market sale | 6.0K | $33.25 | $200K |
| 2025-08-21 | NAMS | NewAmsterdam Pharma Co N.V. | S — Open-market sale | 7.7K | $25.49 | $195K |
| 2025-08-21 | NAMS | NewAmsterdam Pharma Co N.V. | S — Open-market sale | 42.3K | $25.08 | $1.06M |
| 2025-08-21 | NAMS | NewAmsterdam Pharma Co N.V. | S — Open-market sale | 50.0K | $24.29 | $1.21M |
Kastelein Johannes Jacob Pieter is a corporate insider — currently tracked as Insider. InsiderAlpha tracks every SEC Form 4 filing in real time.
Recorded transactions: 0 open-market purchases () and 9 open-market sales ($13.37M) across all tracked filings.
All Form 4 filings, transaction values, and 10b5-1 plan flags are listed on this page and updated in real time as new SEC EDGAR filings are processed.
Open the live Kastelein Johannes Jacob Pieter profile on InsiderAlpha for real-time alerts, AI-scored trade ideas, and full transaction history.