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sellNotable cluster of 2

Louise Frederika Kooij sold $453k of NAMS

Chief Accounting Officer at NewAmsterdam Pharma Co N.V.. 18,073 shares at an average of $25.09, traded Sep 3, 2025, filed Sep 5, 2025.

Warning score
60
Value
$453k
18,073 shares
Holdings after
15,000
-55% from before
From 52-week low
+67%
low $14.90, close $24.88
From 52-week high
-7%
high $26.61, as of Sep 3, 2025

Score components

  • Role
    Officer
    +15
  • Trade size
    $453k at market
    +17
  • Share of holdings sold
    Sold 55% of holdings
    +20
  • Cluster
    2 insiders selling within 14 days
    +8

What happened after comparable sells

Same side and tier, against the S&P 500, at 1, 3 and 6 months. Shown to Pro users; the whole table is on the backtest page.

This signal so far: 1m +13.6%, 3m +30.6%, 6m +10.6%.

Price around the trade, and since

From a quarter before the trade to today. The arrow is the trade, the circle the day the filing reached EDGAR, which is the first day anyone outside could act; the dotted line is the S&P 500 rebased to that day's close.

NAMSOct 12, 2026 · close 21.25
Since filing Sep 5, 2025: -21.3%SPY +21.8% · excess -43.1%

Daily candles, adjusted for splits and dividends. Green arrows are insider buys, red are sells, sized by value; the dashed line is the close on the filing day, the dotted line SPY rebased to it.Charts by TradingView Lightweight Charts™

Rows in this filing

Every transaction in Form 4 0000950170-25-113276, as filed. Open on EDGAR

DateTransactionSharesPriceValueHoldings afterFiled
Sep 3, 2025SOpen-market sale
Ordinary Shares
-18,073$25.09$453k15,000Sep 5, 2025

Related signals

Other insiders at NewAmsterdam Pharma Co N.V. and this insider’s other filings.

ScoreCompanyInsiderValueHoldingsFiled
15Weak
NAMSsell10b5-1
NewAmsterdam Pharma Co N.V.
Johannes Jacob Pieter Kastelein
Chief Scientific Officer
$1.3M
50,246 shares
-42%
38Weak
NAMSbuy
NewAmsterdam Pharma Co N.V.
Michael H. Davidson
Chief Executive Officer
$227k
10,000 shares
+1%
34Weak
NAMSsell 2
NewAmsterdam Pharma Co N.V.
John W Smither
director
$41k
1,600 shares
-15%
33Weak
NAMSsell 210b5-1
NewAmsterdam Pharma Co N.V.
Johannes Jacob Pieter Kastelein
Chief Scientific Officer
$3.4M
125,000 shares
-64%
25Weak
NAMSsell10b5-1
NewAmsterdam Pharma Co N.V.
Louise Frederika Kooij
Chief Accounting Officer
$3.2M
105,000 shares
-81%
25Weak
NAMSsell10b5-1
NewAmsterdam Pharma Co N.V.
Louise Frederika Kooij
Chief Accounting Officer
$1.2M
40,000 shares
-62%
25Weak
NAMSsell10b5-1
NewAmsterdam Pharma Co N.V.
Louise Frederika Kooij
Chief Accounting Officer
$2.3M
65,000 shares
-73%
75Notable
NAMSsell 3
NewAmsterdam Pharma Co N.V.
Louis G Lange
director
$1.4M
44,619 shares
-81%
73Notable
NAMSsell 3
NewAmsterdam Pharma Co N.V.
Louis G Lange
director
$829k
28,186 shares
-100%
40Moderate
NAMSsell 310b5-1
NewAmsterdam Pharma Co N.V.
Johannes Jacob Pieter Kastelein
Chief Scientific Officer
$9.1M
300,000 shares
-173%

Not investment advice. Scores and forward returns are decision support built from public SEC filings and past prices; they describe what happened after comparable filings, not what will happen after this one. Do your own research and size your risk.

Louise Frederika Kooij sold $453k of NAMS | InsiderTell