Insider · SEC Forms 3, 4, 5
CIK 1494730
All transactions
Every Form 4 row this person reported, newest first
Insider · SEC Forms 3, 4, 5
Every Form 4 row this person reported, newest first
Kastelein Johannes Jacob Pieter (CIK 2000389) reported 15 SEC Form 4 insider transactions across 1 companies over the past 18 months (most recent 2026-08-25). Recent activity: Buy NAMS (125,000 shares), Sell NAMS (125,000 shares), Buy NAMS (104,467 shares), Sell NAMS (104,467 shares), Buy NAMS (94,124 shares). Source: SEC Form 4.
| Date | Company | Role | Type | Shares | Value |
|---|---|---|---|---|---|
| 2026-08-25 | NewAmsterdam Pharma Co N.V. (NAMS) | Chief Scientific Officer | Buy | 125,000 | $0 |
| 2026-08-25 | NewAmsterdam Pharma Co N.V. (NAMS) | Chief Scientific Officer | Sell | 125,000 | $3.4M |
| 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 |
Source: SEC Form 4 filings · as of 2026-08-25