FolioLanternBeta
NAMSNewAmsterdam Pharma Co N.V.

Johannes Kastelein

Chief Scientific Officer, Director at NewAmsterdam Pharma Co N.V., as of Oct 2, 2026Sold $15.5M of stock in the past 12 months: 90% under a disclosed plan and 10% with no plan disclosed.

Updated Oct 15, 2026 from SEC filings · covers Oct 16, 2025 to Oct 15, 2026
244K
shares held after the latest filing, NewAmsterdam Pharma Co N.V.
Vested shares reported on Forms 3, 4 and 5 only. Not the insider's whole wealth.
527K
shares sold, past 12 months
7
days with sales
$3.4M
largest single day, Aug 24, 2026
1
company filed for

Share of stake sold at NewAmsterdam Pharma Co N.V. is not shown: most of their shares vested during the period, so a percentage would mislead. Why

Selling by month

Oct 2025 to Oct 2026. Each sale is counted once: under a disclosed plan, else to cover taxes, else no plan disclosed.

Disclosed planNo plan disclosedOne dollar scale for every month; the tallest bar is labeled
OctNovDecJan 2026: $200K under a disclosed planJanFeb 2026: $1.6M no plan disclosedFebMar 2026: $9.1M under a disclosed plan$9.1MMarAprMayJunJulAug 2026: $3.4M under a disclosed planAugSep 2026: $1.3M under a disclosed planSepOct

Pattern

What the filings show, past 12 months. Nothing here rates or predicts.

Roles from filings

Every company we track where this person has filed, newest filing first.

CompanyTitleFirst filingLatest filing
NewAmsterdam Pharma Co N.V. (NAMS)Chief Scientific Officer, DirectorDec 29, 2023Oct 2, 2026

Recent filings

The last 5 days with transactions, newest first, one line per trade date. Each number links to an SEC filing.

This page shows only what this person reported on SEC ownership filings. See the methodology. Spotted something wrong? Report an error.