Johannes Jacob Pieter Kastelein

Chief Scientific Officer · NewAmsterdam Pharma Company

Johannes Jacob Pieter Kastelein (Chief Scientific Officer) filed 5 Form 4 reports in the trailing twelve months (0 purchases, 5 sales), most often in NewAmsterdam Pharma Company N.V. (NAMS). The largest single filing was $9.1M of NAMS (300,000 sh across 3 lots, as filed), executed Mar 5. Data as of Nov 8 2026.

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Return, ttmiAverage return per filing, trailing twelve months

–

no purchases on file

Delay-adjustediThe same average, entered at disclosure dates

–

returns measure stock purchases only

Filings, ttm

0 buys · 5 sells

Median delay

–

measured on stock purchases

Volume, ttmiDollar value disclosed in the trailing twelve months

$15.5M

shares × price, as filed

Last traded

Sep 30

Filed Oct 2

Median ADV $32.2M across their filed names

Open performance→

Volume by month

Buys $0 Sells $18.0M

Shares × price, as filed · by filing month · past 24 months

Sectors filed on

Healthcare 5 filings

Sector per market data · by filing · past 12 months

Most traded names

NAMS

NewAmsterdam Pharma Company N.V. NAMS · 0 buys · 6 sells 6 filings

Recent filings

NAMSSALE NewAmsterdam Pharma Company N.V. View filing → $1.3M
50,246 sh × $25.03
Exec Sep 30
Filed Oct 2 · 4:30 PM ET NAMSSALE NewAmsterdam Pharma Company N.V. View filing → $3.4M
125,000 sh × $26.91
Exec Aug 24
Filed Aug 25 · 4:30 PM ET NAMSSALE NewAmsterdam Pharma Company N.V. View filing → $9.1M
300,000 sh across 3 lots
Exec Mar 5
Filed Mar 9 · 5:30 PM ET NAMSSALE NewAmsterdam Pharma Company N.V. View filing → $1.6M
45,481 sh across 2 lots
Exec Feb 20
Filed Feb 24 · 5:30 PM ET NAMSSALE NewAmsterdam Pharma Company N.V. View filing → $200K
6,000 sh × $33.25
Exec Jan 5
Filed Jan 7 · 5:30 PM ET NAMSSALE NewAmsterdam Pharma Company N.V. View filing → $2.5M
100,000 sh across 3 lots
Exec Aug 21 2025
Filed Aug 25 2025 · 5:30 PM ET