Kastelein Johannes Jacob Pieter Insider Trades & Stock Holdings

Chief Scientific Officer · NewAmsterdam Pharma Company N.V. · Latest filing Sep 30, 2026

Kastelein Johannes Jacob Pieter, Chief Scientific Officer at NewAmsterdam Pharma Company N.V. has 1 Form 4 trade on file since Sep 30, 2026. Open-market activity: 0 purchases ($0) and 1 sale ($1.26M), net -$1.26M. Latest filing: disposed of 50.25K shares of $NAMS on Sep 30, 2026 at $25.03.

Trades on file

1

Open-market bought

$0

Open-market sold

$1.26M

Net open-market

-$1.26M

Latest filing

Sep 30, 2026

All insider trades by Kastelein Johannes Jacob Pieter

Date	Ticker	Type	Shares	Price	Value	Owned after	ΔOwn	1W	1M	6M	Role	Filing	Story
Sep 30, 2026	$NAMS	Sell (Open-market sale) 10b5-1	50.25K	$25.03	$1.26M			-9.0%			Chief Scientific Officer		—

"Buy" means shares acquired on the Form 4 (including grants and option exercises); "Sell" means shares disposed. 1W / 1M / 6M = how the stock moved after the trade.

Stocks Kastelein Johannes Jacob Pieter traded

• $NAMS

Frequently asked questions

Has Kastelein Johannes Jacob Pieter been buying or selling stock?

Kastelein Johannes Jacob Pieter has 0 open-market purchases and 1 open-market sale on file, net -$1.26M. Grants, option exercises and tax withholding are listed separately because they are not open-market trades.

What was Kastelein Johannes Jacob Pieter's latest insider trade?

disposed of 50.25K shares of $NAMS on Sep 30, 2026 at $25.03.

Data comes from public SEC Form 4 and 13F filings and STOCK Act disclosures. Dates are the trade or filing date reported. This page is for research only and is not investment advice.