Kastelein Johannes Jacob Pieter (CIK 2000389) reported 16 SEC Form 4 insider transactions across 1 companies over the past 18 months (most recent 2026-03-09). Recent activity: Buy NAMS (104,467 shares), Sell NAMS (104,467 shares), Buy NAMS (94,124 shares), Sell NAMS (94,124 shares), Buy NAMS (101,409 shares). Source: SEC Form 4.
| Date | Company | Role | Type | Shares | Value |
|---|---|---|---|---|---|
| 2026-03-09 | NewAmsterdam Pharma Co N.V. (NAMS) | Chief Scientific Officer | Buy | 104,467 | $0 |
| 2026-03-09 | NewAmsterdam Pharma Co N.V. (NAMS) | Chief Scientific Officer | Sell | 104,467 | $3.2M |
| 2026-03-09 | NewAmsterdam Pharma Co N.V. (NAMS) | Chief Scientific Officer | Buy | 94,124 | $0 |
| 2026-03-09 | NewAmsterdam Pharma Co N.V. (NAMS) | Chief Scientific Officer | Sell | 94,124 | $2.9M |
| 2026-03-09 | NewAmsterdam Pharma Co N.V. (NAMS) | Chief Scientific Officer | Buy | 101,409 | $0 |
| 2026-03-09 | NewAmsterdam Pharma Co N.V. (NAMS) | Chief Scientific Officer | Sell | 101,409 | $3.1M |
| 2026-02-24 | NewAmsterdam Pharma Co N.V. (NAMS) | Chief Scientific Officer | Sell | 14,692 | $514,220 |
| 2026-02-24 | NewAmsterdam Pharma Co N.V. (NAMS) | Chief Scientific Officer | Sell | 30,789 | $1.1M |
| 2026-01-07 | NewAmsterdam Pharma Co N.V. (NAMS) | Chief Scientific Officer | Sell | 6,000 | $199,500 |
| 2026-01-07 | NewAmsterdam Pharma Co N.V. (NAMS) | Chief Scientific Officer | Buy | 25,500 | $0 |
| 2025-08-25 | NewAmsterdam Pharma Co N.V. (NAMS) | Chief Scientific Officer | Sell | 50,000 | $1.2M |
| 2025-08-25 | NewAmsterdam Pharma Co N.V. (NAMS) | Chief Scientific Officer | Sell | 42,342 | $1.1M |
| 2025-08-25 | NewAmsterdam Pharma Co N.V. (NAMS) | Chief Scientific Officer | Sell | 7,658 | $195,202 |
| 2025-03-28 | NewAmsterdam Pharma Co N.V. (NAMS) | Chief Scientific Officer | Buy | 19,302 | $0 |
| 2025-03-28 | NewAmsterdam Pharma Co N.V. (NAMS) | Chief Scientific Officer | Buy | 45,481 | $0 |
| 2025-03-26 | NewAmsterdam Pharma Co N.V. (NAMS) | Chief Scientific Officer | Buy | 150,000 | $0 |
Source: SEC Form 4 filings · as of 2026-03-09