Louise Frederika Kooij - 23 Dec 2025 Form 4 Insider Report for NewAmsterdam Pharma Co N.V. (NAMS)

Role
Chief Accounting Officer
Signature
/s/ Louise Kooij
Issuer symbol
NAMS
Transactions as of
23 Dec 2025
Net transactions value
-$3,742,241
Form type
4
Filing time
29 Dec 2025, 17:14:14 UTC
Previous filing
10 Sep 2025
Next filing
07 Jan 2026
SEC
View on sec.gov

Reporting Owners (1)

Name Relationship Address Signature Signature date CIK
Kooij Louise Frederika Chief Accounting Officer C/O NEWAMSTERDAM PHARMA COMPANY N.V., GOOIMEER 2-35, NAARDEN, NETHERLANDS /s/ Louise Kooij 29 Dec 2025 0002004379

Transactions Table

Type Sym Class Transaction Value $ Shares Change % * Price $ Shares After Date Ownership Footnotes
transaction NAMS Ordinary Shares Options Exercise $751,170 +75,117 +501% $10.00 90,117 23 Dec 2025 Direct
transaction NAMS Ordinary Shares Sale $2,719,987 -75,117 -83% $36.21 15,000 23 Dec 2025 Direct F1
transaction NAMS Ordinary Shares Options Exercise $260,110 +26,011 +173% $10.00 41,011 24 Dec 2025 Direct
transaction NAMS Ordinary Shares Sale $928,072 -26,011 -63% $35.68 15,000 24 Dec 2025 Direct F2
transaction NAMS Ordinary Shares Options Exercise $388,720 +38,872 +259% $10.00 53,872 26 Dec 2025 Direct
transaction NAMS Ordinary Shares Options Exercise $54,500 +5,000 +9.3% $10.90 58,872 26 Dec 2025 Direct
transaction NAMS Ordinary Shares Sale $1,548,682 -43,872 -75% $35.30 15,000 26 Dec 2025 Direct F3

Derivative Securities (e.g., puts, calls, warrants, options, convertible securities)

Type Sym Class Transaction Value $ Shares Change % * Price $ Shares After Date Underlying Class Amount Exercise Price Ownership Footnotes
transaction NAMS Option (right to buy) Options Exercise $0 -75,117 -27% $0.000000 204,898 23 Dec 2025 Ordinary Shares 75,117 $10.00 Direct F4
transaction NAMS Option (right to buy) Options Exercise $0 -26,011 -13% $0.000000 178,887 24 Dec 2025 Ordinary Shares 26,011 $10.00 Direct F4
transaction NAMS Option (right to buy) Options Exercise $0 -38,872 -22% $0.000000 140,015 26 Dec 2025 Ordinary Shares 38,872 $10.00 Direct F4
transaction NAMS Option (right to buy) Options Exercise $0 -5,000 -2.2% $0.000000 218,134 26 Dec 2025 Ordinary Shares 5,000 $10.90 Direct F5
* An asterisk sign (*) next to the price indicates that the price is likely invalid.

Buy Plan / Sale Plan: These are also open market purchases/sales of shares, but in this case the transaction is part of a trading plan. Rule 10b5-1 allows insiders to setup a trading plan to buy/sell stocks over a certain period of time. Since the purchases/sales are predetermined, this protects the insiders from violating insider trading law.

Transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c).

Explanation of Responses:

Id Content
F1 The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $35.88 to $36.75 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 The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $35.24 to $36.09 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.
F3 The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $34.85 to $35.56 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.
F4 The option was granted on November 22, 2022. The shares underlying the option vest in equal monthly installments over four years, with the first 1/48th of such shares vesting on December 1, 2022 and the remaining installments vesting on each one-month anniversary of the grant date, subject to the Reporting Person's continued service through each such date.
F5 The option was granted on January 1, 2023. 25% of the shares underlying the option vest on 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.