MetaCap

NewAmsterdam Pharma N.V. Insider Trades

NASDAQ: NAMSHealth CareBiotechnology: Pharmaceutical PreparationsUSD

21.58+0.315 (+1.48%)

At close: Oct 9, 4:00 PM ET · Delayed 15 min

Last 12 months

Purchases
1 · $226.50K
Sales
43 · $63.25M
Shares bought / sold
10.00K / 1.97M
Net activity
Net selling $63.0 million

NewAmsterdam Pharma N.V. insider activity

Over the last 12 months, NewAmsterdam Pharma N.V. insiders reported 81 transactions on SEC Form 4: 1 open-market purchase and 43 sales. Insiders bought $226,500 and sold $63.3 million worth of stock, for net insider selling of $63.0 million. The largest seller was Davidson Michael H., with $25.3 million in reported sales.

The most recent filing shows Kastelein Johannes Jacob Pieter (Chief Scientific Officer) reporting a transaction in 50,246 shares on Sep 30, 2026. Insider sales are common for compensation, tax and diversification reasons, while open-market purchases are rarer; tracking both helps put NAMS's ownership changes in context.

Summary generated from market data by MetaCap's automated system. Methodology

NAMS insider transactions

NewAmsterdam Pharma N.V. insider transactions
DateInsiderTypeSharesValueFiling
Sep 30, 2026Kastelein Johannes Jacob PieterChief Scientific OfficerSale50,246$1.26MForm 4
Sep 30, 2026Kastelein Johannes Jacob PieterChief Scientific OfficerOption exercise50,246—Form 4
Sep 14, 2026Davidson Michael H.Chief Executive OfficerBuy10,000$226.50KForm 4
Sep 4, 2026Smither John WDirectorSale1,600$40.51KForm 4
Sep 1, 2026Gunning Robert WilliamVice President, ControllerAward3,200—Form 4
Aug 24, 2026Kastelein Johannes Jacob PieterChief Scientific OfficerSale125,000$3.36MForm 4
Aug 24, 2026Kastelein Johannes Jacob PieterChief Scientific OfficerOption exercise125,000—Form 4
Jul 20, 2026Kooij Louise FrederikaChief Accounting OfficerSale2,915$92.43KForm 4
Jul 20, 2026Kooij Louise FrederikaChief Accounting OfficerSale31,885$990.03KForm 4
Jul 20, 2026Kooij Louise FrederikaChief Accounting OfficerSale70,200$2.10MForm 4
Jul 20, 2026Kooij Louise FrederikaChief Accounting OfficerOption exercise80,000$893.60KForm 4
Jul 20, 2026Kooij Louise FrederikaChief Accounting OfficerOption exercise25,000$297.50KForm 4
Jun 22, 2026Kooij Louise FrederikaChief Accounting OfficerSale300$9.22KForm 4
Jun 22, 2026Kooij Louise FrederikaChief Accounting OfficerSale39,700$1.20MForm 4
Jun 22, 2026Kooij Louise FrederikaChief Accounting OfficerOption exercise15,000$178.50KForm 4
Jun 22, 2026Kooij Louise FrederikaChief Accounting OfficerOption exercise25,000$272.50KForm 4
May 26, 2026Kooij Louise FrederikaChief Accounting OfficerSale65,000$2.32MForm 4
May 26, 2026Kooij Louise FrederikaChief Accounting OfficerOption exercise5,000$54.50KForm 4
May 26, 2026Kooij Louise FrederikaChief Accounting OfficerOption exercise60,000$600.00KForm 4
Mar 11, 2026LANGE LOUIS GDirectorSale446$13.93KForm 4
Mar 11, 2026LANGE LOUIS GDirectorSale44,173$1.34MForm 4
Mar 9, 2026Kastelein Johannes Jacob PieterChief Scientific OfficerSale101,409$3.07MForm 4
Mar 9, 2026Kastelein Johannes Jacob PieterChief Scientific OfficerOption exercise101,409—Form 4
Mar 9, 2026LANGE LOUIS GDirectorOption exercise44,619$513.12KForm 4
Mar 6, 2026Kastelein Johannes Jacob PieterChief Scientific OfficerSale94,124$2.85MForm 4
Mar 6, 2026Kastelein Johannes Jacob PieterChief Scientific OfficerOption exercise94,124—Form 4
Mar 6, 2026LANGE LOUIS GDirectorSale28,186$828.95KForm 4
Mar 5, 2026Kastelein Johannes Jacob PieterChief Scientific OfficerSale104,467$3.17MForm 4
Mar 5, 2026Kastelein Johannes Jacob PieterChief Scientific OfficerOption exercise104,467—Form 4
Mar 2, 2026Davidson Michael H.Chief Executive OfficerSale443,707$14.75MForm 4
Mar 2, 2026Davidson Michael H.Chief Executive OfficerOption exercise443,707—Form 4
Feb 26, 2026Davidson Michael H.Chief Executive OfficerSale17,924$617.30KForm 4
Feb 26, 2026Davidson Michael H.Chief Executive OfficerSale165,408$5.56MForm 4
Feb 26, 2026Davidson Michael H.Chief Executive OfficerOption exercise183,332—Form 4
Feb 25, 2026Davidson Michael H.Chief Executive OfficerSale1,300$47.68KForm 4
Feb 25, 2026Davidson Michael H.Chief Executive OfficerSale10,436$375.28KForm 4
Feb 25, 2026Davidson Michael H.Chief Executive OfficerSale46,517$1.63MForm 4
Feb 25, 2026Davidson Michael H.Chief Executive OfficerOption exercise58,253—Form 4
Feb 24, 2026Davidson Michael H.Chief Executive OfficerSale3,161$115.25KForm 4
Feb 24, 2026Davidson Michael H.Chief Executive OfficerSale61,547$2.22MForm 4
Feb 24, 2026Davidson Michael H.Chief Executive OfficerOption exercise64,708—Form 4
Feb 20, 2026Kastelein Johannes Jacob PieterChief Scientific OfficerSale30,789$1.09MForm 4
Feb 20, 2026Kastelein Johannes Jacob PieterChief Scientific OfficerSale14,692$514.22KForm 4
Jan 28, 2026Kooij Louise FrederikaChief Accounting OfficerSale32,612$1.04MForm 4
Jan 28, 2026Kooij Louise FrederikaChief Accounting OfficerOption exercise32,612$355.47KForm 4
Jan 27, 2026Kooij Louise FrederikaChief Accounting OfficerSale39,816$1.30MForm 4
Jan 27, 2026Kooij Louise FrederikaChief Accounting OfficerOption exercise39,816$433.99KForm 4
Jan 26, 2026Kooij Louise FrederikaChief Accounting OfficerSale309$10.34KForm 4
Jan 26, 2026Kooij Louise FrederikaChief Accounting OfficerSale34,091$1.12MForm 4
Jan 26, 2026Kooij Louise FrederikaChief Accounting OfficerOption exercise34,400$374.96KForm 4
Jan 23, 2026Kooij Louise FrederikaChief Accounting OfficerSale12,767$438.80KForm 4
Jan 23, 2026Kooij Louise FrederikaChief Accounting OfficerSale25,405$849.54KForm 4
Jan 23, 2026Kooij Louise FrederikaChief Accounting OfficerOption exercise38,172$416.07KForm 4
Jan 21, 2026Somaiya Mayur IanChief Financial OfficerSale24,362$823.44KForm 4
Jan 21, 2026Somaiya Mayur IanChief Financial OfficerSale15,422$512.78KForm 4
Jan 21, 2026Somaiya Mayur IanChief Financial OfficerOption exercise39,784$368.40KForm 4
Jan 20, 2026Somaiya Mayur IanChief Financial OfficerSale19,604$634.78KForm 4
Jan 20, 2026Somaiya Mayur IanChief Financial OfficerSale39,712$1.26MForm 4
Jan 20, 2026Somaiya Mayur IanChief Financial OfficerSale900$27.58KForm 4
Jan 20, 2026Somaiya Mayur IanChief Financial OfficerOption exercise60,216$557.60KForm 4
Jan 7, 2026Somaiya Mayur IanChief Financial OfficerAward25,500—Form 4
Jan 7, 2026Kooij Louise FrederikaChief Accounting OfficerAward12,000—Form 4
Jan 7, 2026Kastelein Johannes Jacob PieterChief Scientific OfficerAward25,500—Form 4
Jan 7, 2026Smither John WDirectorAward3,400—Form 4
Jan 7, 2026Lewis WilliamDirectorAward3,400—Form 4
Jan 7, 2026Gulfo Adele M.DirectorAward3,400—Form 4
Jan 7, 2026LANGE LOUIS GDirectorAward3,400—Form 4
Jan 7, 2026McKenna Mark C.DirectorAward3,400—Form 4
Jan 7, 2026Davidson Michael H.Chief Executive OfficerAward81,000—Form 4
Jan 7, 2026Davidson Michael H.Chief Executive OfficerSale11,582—Form 4
Jan 7, 2026van der Kamp Hilde JohannaDirectorAward3,400—Form 4
Jan 5, 2026Somaiya Mayur IanChief Financial OfficerSale5,118$170.17KForm 4
Jan 5, 2026Kooij Louise FrederikaChief Accounting OfficerSale2,647$88.01KForm 4
Jan 5, 2026Kastelein Johannes Jacob PieterChief Scientific OfficerSale6,000$199.50KForm 4
Dec 26, 2025Kooij Louise FrederikaChief Accounting OfficerSale43,872$1.55MForm 4
Dec 26, 2025Kooij Louise FrederikaChief Accounting OfficerOption exercise5,000$54.50KForm 4
Dec 26, 2025Kooij Louise FrederikaChief Accounting OfficerOption exercise38,872$388.72KForm 4
Dec 24, 2025Kooij Louise FrederikaChief Accounting OfficerSale26,011$928.07KForm 4
Dec 24, 2025Kooij Louise FrederikaChief Accounting OfficerOption exercise26,011$260.11KForm 4
Dec 23, 2025Kooij Louise FrederikaChief Accounting OfficerSale75,117$2.72MForm 4
Dec 23, 2025Kooij Louise FrederikaChief Accounting OfficerOption exercise75,117$751.17KForm 4
Sep 15, 2025Topper James NDirectorBuy660$15.64KForm 4
Sep 9, 2025Kooij Louise FrederikaChief Accounting OfficerSale96,896$2.53MForm 4
Sep 9, 2025Kooij Louise FrederikaChief Accounting OfficerSale53,104$1.34MForm 4
Sep 9, 2025Kooij Louise FrederikaChief Accounting OfficerOption exercise150,000$1.50MForm 4
Sep 8, 2025Topper James NDirectorBuy1,260$31.49KForm 4
Sep 3, 2025Kooij Louise FrederikaChief Accounting OfficerSale18,073$453.45KForm 4
Sep 2, 2025Kooij Louise FrederikaChief Accounting OfficerOption exercise18,073—Form 4
Aug 25, 2025Kooij Louise FrederikaChief Accounting OfficerSale8,269$205.57KForm 4
Aug 22, 2025Kastelein Johannes Jacob PieterChief Scientific OfficerSale7,658$195.20KForm 4
Aug 22, 2025Kastelein Johannes Jacob PieterChief Scientific OfficerSale42,342$1.06MForm 4
Aug 21, 2025Kastelein Johannes Jacob PieterChief Scientific OfficerSale50,000$1.21MForm 4
Aug 11, 2025Topper James NDirectorBuy471$11.29KForm 4
Jul 16, 2025Kling Douglas FChief Operating OfficerSale51,043$1.08MForm 4
Jul 16, 2025Kling Douglas FChief Operating OfficerOption exercise51,043$556.37KForm 4
Jul 15, 2025Kling Douglas FChief Operating OfficerSale3,544$78.39KForm 4
Jul 15, 2025Kling Douglas FChief Operating OfficerSale44,025$941.25KForm 4
Jul 15, 2025Kling Douglas FChief Operating OfficerOption exercise47,569$518.50KForm 4
Jun 25, 2025Topper James NDirectorBuy1,260$23.01KForm 4
Jun 24, 2025Topper James NDirectorBuy2,520$46.45KForm 4

Transaction codes follow SEC Form 4: P = open-market purchase, S = open-market sale, A = grant or award, M = option exercise, F = shares withheld for taxes. About Form 4

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