KOOIJ LOUISE FREDERIKA (Chief Accounting Officer) sold 74.9% of their position (72.57K shares) of NEWAMSTERDAM PHARMA CO N.V. on the open market

Open‑market sale worth $2.42M — a major position exit. Review remaining holdings and any 10b5‑1 plan disclosures.

S · 4 sales

KOOIJ LOUISE FREDERIKA

Filed: 1/27/2026ACC: 0001193125-26-025012

InsiderKOOIJ LOUISE FREDERIKACIK 2004379

→

IssuerNEWAMSTERDAM PHARMA CO N.V.CIK 1936258

Officer· Chief Accounting Officer

Since Jan 2026

-72.57K

Net shares

Net seller

$2.42M

Total sold

Open market trades

0B · 4S

Total transactions

72.57K acquired · 145.14K disposed

Non-Derivative Transactions6

Ordinary Shares

Direct

M · Option Exercise

+38.17K

Price / share

$10.90

Trade value

$416.07K

% of position

156.7%

1/23/2026

24.35K→62.52K

Ordinary Shares

Direct

S · Sale

−25.41K

Price / share

$33.44

Trade value

$849.54K

% of position

40.6%

1/23/2026

62.52K→37.12K

Ordinary Shares

Direct

S · Sale

−12.77K

Price / share

$34.37

Trade value

$438.80K

% of position

34.4%

1/23/2026

37.12K→24.35K

Ordinary Shares

Direct

M · Option Exercise

+34.40K

Price / share

$10.90

Trade value

$374.96K

% of position

141.3%

1/26/2026

24.35K→58.75K

Ordinary Shares

Direct

S · Sale

−34.09K

Price / share

$32.77

Trade value

$1.12M

% of position

58.0%

1/26/2026

58.75K→24.66K

Ordinary Shares

Direct

S · Sale

−309.00

Price / share

$33.45

Trade value

$10.34K

% of position

1.3%

1/26/2026

24.66K→24.35K

Total

Net shares

+0.00

Net value

-$1.62M

Security	Date	Type	Shares	Price / Share	Trade Value	% of Position	Held Before	Held After
Ordinary Shares Direct	1/23/2026	M · Option Exercise	+38.17K	$10.90	$416.07K	156.7%	24.35K	62.52K
Ordinary Shares Direct	1/23/2026	S · Sale	−25.41K	$33.44	$849.54K	40.6%	62.52K	37.12K
Ordinary Shares Direct	1/23/2026	S · Sale	−12.77K	$34.37	$438.80K	34.4%	37.12K	24.35K
Ordinary Shares Direct	1/26/2026	M · Option Exercise	+34.40K	$10.90	$374.96K	141.3%	24.35K	58.75K
Ordinary Shares Direct	1/26/2026	S · Sale	−34.09K	$32.77	$1.12M	58.0%	58.75K	24.66K
Ordinary Shares Direct	1/26/2026	S · Sale	−309.00	$33.45	$10.34K	1.3%	24.66K	24.35K
Total			+0.00		-$1.62M

Derivative Transactions2

Option (right to buy)

Direct

M · Option Exercise

Converts to

Ordinary Shares

38.17K shares

−38.17K

Strike price

10.90

Held after

179.96K

Exercisable

—

1/23/2026

Option (right to buy)

Direct

M · Option Exercise

Converts to

Ordinary Shares

34.40K shares

−34.40K

Strike price

10.90

Held after

145.56K

Exercisable

—

1/26/2026

Security	Converts To	Date	Type	Shares	Strike Price	Exercisable	Held After
Option (right to buy) Direct	Ordinary Shares38.17K shares	1/23/2026	M · Option Exercise	−38.17K	10.90	—	179.96K
Option (right to buy) Direct	Ordinary Shares34.40K shares	1/26/2026	M · Option Exercise	−34.40K	10.90	—	145.56K