Who
Johannes Jacob Pieter Kastelein
Chief Scientific Officer
Company insider
Files Form 4 as: Chief Scientific Officer, NewAmsterdam Pharma Company.
In numbers
- Trades disclosed
- 53
- Buys
- 0
- Sells
- 10
- Bought
- $0
- Sold
- $36.3M
- Companies
- 1
- Companies where not an officer
- 0
- First trade
- 1 Jan 2024
- Last trade
- 30 Sep 2026
- Last filed
- 2 Oct 2026
Companies traded
Activity over time
1 Nov 2024 – 1 Oct 2026
Buys above the line, sells below, each month.
Every trade
| Traded | Company | What | Amount | |
|---|---|---|---|---|
| 30 Sep 2026filed 2 Oct 2026 | NAMS NewAmsterdam Pharma CompanyBiotechnology | SEC FORM 4 Code M | —50,246 | filing |
| 30 Sep 2026filed 2 Oct 2026 | NAMS NewAmsterdam Pharma CompanyBiotechnology | SEC FORM 4 Sold | $1.3M50,246 at $25.03 | filing |
| 30 Sep 2026filed 2 Oct 2026 | NAMS NewAmsterdam Pharma Companyoption or derivative · Biotechnology | SEC FORM 4 Code M | —50,246 at $0.00 | filing |
| 24 Aug 2026filed 25 Aug 2026 | NAMS NewAmsterdam Pharma CompanyBiotechnology | SEC FORM 4 Code M | —125,000 | filing |
| 24 Aug 2026filed 25 Aug 2026 | NAMS NewAmsterdam Pharma CompanyBiotechnology | SEC FORM 4 Sold | $3.4M125,000 at $26.91 | filing |
| 24 Aug 2026filed 25 Aug 2026 | NAMS NewAmsterdam Pharma Companyoption or derivative · Biotechnology | SEC FORM 4 Code M | —125,000 at $0.00 | filing |
| 24 Aug 2026filed 25 Aug 2026 | NAMS NewAmsterdam Pharma Companyoption or derivative · Biotechnology | SEC FORM 4 Code M | —125,000 at $0.00 | filing |
| 24 Aug 2026filed 25 Aug 2026 | NAMS NewAmsterdam Pharma CompanyBiotechnology | SEC FORM 4 Code M | —125,000 | filing |
| 24 Aug 2026filed 25 Aug 2026 | NAMS NewAmsterdam Pharma CompanyBiotechnology | SEC FORM 4 Sold | $3.4M125,000 at $26.91 | filing |
| 9 Mar 2026filed 9 Mar 2026 | NAMS NewAmsterdam Pharma Companyoption or derivative · Biotechnology | SEC FORM 4 Code M | —101,409 at $0.00 | filing |
| 9 Mar 2026filed 9 Mar 2026 | NAMS NewAmsterdam Pharma CompanyBiotechnology | SEC FORM 4 Code M | —101,409 | filing |
| 9 Mar 2026filed 9 Mar 2026 | NAMS NewAmsterdam Pharma CompanyBiotechnology | SEC FORM 4 Sold | $3.1M101,409 at $30.29 | filing |
| 9 Mar 2026filed 9 Mar 2026 | NAMS NewAmsterdam Pharma CompanyBiotechnology | SEC FORM 4 Code M | —101,409 | filing |
| 9 Mar 2026filed 9 Mar 2026 | NAMS NewAmsterdam Pharma CompanyBiotechnology | SEC FORM 4 Sold | $3.1M101,409 at $30.29 | filing |
| 9 Mar 2026filed 9 Mar 2026 | NAMS NewAmsterdam Pharma Companyoption or derivative · Biotechnology | SEC FORM 4 Code M | —101,409 at $0.00 | filing |
| 6 Mar 2026filed 9 Mar 2026 | NAMS NewAmsterdam Pharma CompanyBiotechnology | SEC FORM 4 Code M | —94,124 | filing |
| 6 Mar 2026filed 9 Mar 2026 | NAMS NewAmsterdam Pharma Companyoption or derivative · Biotechnology | SEC FORM 4 Code M | —94,124 at $0.00 | filing |
| 6 Mar 2026filed 9 Mar 2026 | NAMS NewAmsterdam Pharma CompanyBiotechnology | SEC FORM 4 Sold | $2.9M94,124 at $30.32 | filing |
| 6 Mar 2026filed 9 Mar 2026 | NAMS NewAmsterdam Pharma Companyoption or derivative · Biotechnology | SEC FORM 4 Code M | —94,124 at $0.00 | filing |
| 6 Mar 2026filed 9 Mar 2026 | NAMS NewAmsterdam Pharma CompanyBiotechnology | SEC FORM 4 Code M | —94,124 | filing |
News
Head-To-Head Analysis: Rallybio (NASDAQ:RLYB) versus NewAmsterdam Pharma (NASDAQ:NAMS)NAMS · dailypolitical.com · 14 Oct 2026Analyzing NewAmsterdam Pharma (NASDAQ:NAMS) & Grifols (NASDAQ:GRFS)NAMS · tickerreport.com · 14 Oct 2026
0 headlines in the last 90 days name Johannes Jacob Pieter Kastelein; 2 articles from the last 14 days about the 1 company they traded most, at most three about any one of them.