InsiderTrades

Form 4 for NAMS NewAmsterdam Pharma Co N.V.

Accepted 2026-08-25 16:30:07 ET · period of report 2026-08-24 · accession 0001193125-26-365202 · SEC index · Original document

Summary rows

Aggregated the way they appear in lists: one row per insider, transaction code and security table.

X Filed Traded Ticker Insider Title Type Price Qty Owned ΔOwn Value
DTI 2026-08-25 16:30 2026-08-24 NAMS Kastelein Johannes Jacob Pieter CSO, Dir M - OptEx — +125.0K 194.3K +180% —
DTI 2026-08-25 16:30 2026-08-24 NAMS Kastelein Johannes Jacob Pieter CSO, Dir S - Sale+OE $26.91 -125.0K 69.3K -64% -$3.36M
DTI 2026-08-25 16:30 2026-08-24 NAMS Kastelein Johannes Jacob Pieter CSO, Dir M - OptEx $0.00 -125.0K 395.2K -24% $0

Purchase Sale Sale after option exercise All abbreviations

Every reported transaction

#TableSecurityDateCodeA/DSharesPriceOwned afterOwnExercise / expiryUnderlyingFootnotes
1 Common Ordinary Shares 2026-08-24 M A 125,000 — 194,302 I See footnotes — — (F1) The exercise price of the option is EUR 1.16392. (F2) These Ordinary Shares are held by Futurum B.V. ("Futurum") through NAP PoolCo B.V. ("PoolCo") for the benefit of the Reporting Person. The Reporting Person exercises sole voting and investment control over the securities held by Futurum through PoolCo. PoolCo has no voting or investment control or pecuniary interest in the securities held on behalf of Futurum.
2 Common Ordinary Shares 2026-08-24 S D 125,000 $26.91 69,302 I See footnotes — — (F3) The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $26.72 to $27.70 per share. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold in each transaction. (F2) These Ordinary Shares are held by Futurum B.V. ("Futurum") through NAP PoolCo B.V. ("PoolCo") for the benefit of the Reporting Person. The Reporting Person exercises sole voting and investment control over the securities held by Futurum through PoolCo. PoolCo has no voting or investment control or pecuniary interest in the securities held on behalf of Futurum.
3 Derivative Option (right to buy) 2026-08-24 M D 125,000 $0.00 395,229 I See footnote — · — to 2031-07-06 125,000 Ordinary Shares (F1) The exercise price of the option is EUR 1.16392. (F5) The option was granted on November 22, 2022 to replace an option originally granted on July 6, 2021 which was cancelled in connection with the consummation of NewAmsterdam Pharma Company N.V.'s business combination with Frazier Lifesciences Acquisition Corporation. 292,214 of the shares underlying the option immediately vested on the grant date. 25% of the remaining shares underlying the option vested on January 1, 2021, the one-year anniversary of vesting start date, with the remaining shares vesting in equal monthly installments thereafter for three years, subject to the Reporting Person's continued service through each such date. (F6) The option was granted to and is held by Futurum through PoolCo for the benefit of the Reporting Person. The Reporting Person exercises sole voting and investment control over the securities held by Futurum through PoolCo. PoolCo has no voting or investment control or pecuniary interest in the securities held on behalf of Futurum. Upon exercise of the option, the Ordinary Shares were issued to Futurum directly, pursuant to a written agreement among Futurum, PoolCo and the Issuer.