Kastelein Johannes Jacob Pieter
Chief Scientific Officer
Kastelein Johannes Jacob Pieter has filed 4 SEC Form 4 filings (12 transaction rows) across 1 company, with disclosures dating back to 2026. 4 of those filings fall inside the rolling window. Most recent filing: Aug 25, 2026.
On the most recent filing, Kastelein Johannes Jacob Pieter is listed as Chief Scientific Officer at NewAmsterdam Pharma Co N.V. Inside the rolling window, Kastelein Johannes Jacob Pieter reported no open-market purchases and 6 open-market sales totaling $14.3M in NAMS. The largest disclosed transaction in the window is a sale of 125,000 NAMS shares on Aug 24, 2026, worth $3.4M.
Companies traded
Other insiders at NAMS
Insider Buying
$0
reported purchases (SEC code P)
Insider Selling
$14.3M
reported sales (SEC code S)
Companies
1
in the rolling window
| Source | |||||||
|---|---|---|---|---|---|---|---|
| NAMS | Chief Scientific Officer | Sale | 125,000 | $3.4M | Aug 25 | SEC ↗ | |
| NAMS | Chief Scientific Officer | Sale | 104,467 | $3.2M | Mar 9 | SEC ↗ | |
| NAMS | Chief Scientific Officer | Sale | 94,124 | $2.9M | Mar 9 | SEC ↗ | |
| NAMS | Chief Scientific Officer | Sale | 101,409 | $3.1M | Mar 9 | SEC ↗ | |
| NAMS | Chief Scientific Officer | Sale | 45,481 | $1.6M | Feb 24 | SEC ↗ | |
| NAMS | Chief Scientific Officer | Sale | 6,000 | $200K | Jan 7 | SEC ↗ |
Frequently asked questions
How many SEC Form 4 filings has Kastelein Johannes Jacob Pieter made?
Kastelein Johannes Jacob Pieter has filed 4 SEC Form 4 filings (12 transaction rows) across 1 company since 2026.
Which companies does Kastelein Johannes Jacob Pieter trade?
Kastelein Johannes Jacob Pieter has filed SEC Form 4 disclosures for 1 company, including NAMS.
When was Kastelein Johannes Jacob Pieter's most recent SEC Form 4 filing?
Kastelein Johannes Jacob Pieter's most recent SEC Form 4 filing on Tracefour is dated Aug 25, 2026.
What is Kastelein Johannes Jacob Pieter's job title?
On the most recent SEC Form 4 filings tracked by Tracefour, Kastelein Johannes Jacob Pieter is listed as Chief Scientific Officer.
What is Kastelein Johannes Jacob Pieter's total buy and sell value in the current window?
Inside the rolling retention window, Kastelein Johannes Jacob Pieter bought $0 and sold $14.3M based on SEC Form 4 filings.
What was Kastelein Johannes Jacob Pieter's largest disclosed transaction?
The largest disclosed transaction in the current window is a sale of 125,000 NAMS shares on 2026-08-24, worth $3.4M, per SEC Form 4 filings.