Jane Street’s NewAmsterdam Pharma NAMS Stock Holding History

Jane Street’s Portfolio NAMS Stock Details NAMS Fund Activity

Bought

Maintained

Sold

Quarter	Market Value	Status	Shares	Change in Stake	Trade Value	Portfolio Weight	Portfolio Position
2026 Q2	$407K	Sell	12,000 -29,000	-71%	-$956K	﹤0.01%	8508
2026 Q1	$1.31M	Sell	41,000 -23,900	-37%	-$779K	﹤0.01%	5908
2025 Q4	$2.28M	Buy	+64,900	New	+$2.36M	﹤0.01%	4564
2025 Q2	–	Sell	-29,900	Closed	-$612K	–	10444
2025 Q1	$612K	Sell	29,900 -54,900	-65%	-$1.22M	﹤0.01%	6490
2024 Q4	$2.18M	Buy	84,800 +64,800	+324%	+$1.38M	﹤0.01%	3953
2024 Q3	$332K	Buy	+20,000	New	+$346K	﹤0.01%	7859

Other funds holding NAMS

FLSM

Frazier Life Sciences Management Palo Alto, California $4.59B AUM 237.58% 1-Year Est. Return

Capital World Investors Los Angeles, California $846B AUM 46.74% 1-Year Est. Return

Fidelity Investments Boston, Massachusetts $2.3T AUM 54.33% 1-Year Est. Return

RCM

RA Capital Management Boston, Massachusetts $11.5B AUM 168.77% 1-Year Est. Return

FIS

FCPM III Services Naarden, Netherlands $750M AUM 127.27% 1-Year Est. Return

Deerfield Management New York $9.59B AUM 113.36% 1-Year Est. Return

Viking Global Investors Stamford, Connecticut $35.1B AUM 21.36% 1-Year Est. Return

BCLSI

Bain Capital Life Sciences Investors Boston, Massachusetts $1.68B AUM 126.09% 1-Year Est. Return

Maverick Capital Dallas, Texas $11.3B AUM 76.6% 1-Year Est. Return

DFO

Duquesne Family Office New York $5.21B AUM 87.01% 1-Year Est. Return

Jane Street's NAMS Position: Q2 2026 in Review

Jane Street increased its NewAmsterdam Pharma (NAMS) stake by 187% in Q2 2026, buying an estimated $10.2M and bringing the position to 474,236 shares worth $16.1M. The position accounts for ﹤0.01% of the portfolio, ranked #2354.

Jane Street first reported a position in NAMS in Q4 2025 and has held it in 3 quarters since. 195 funds tracked by Wall St. Rank hold NAMS as of Q2 2026.

Jane Street held 474,236 shares of NewAmsterdam Pharma worth $16.1M as of Q2 2026.
Jane Street bought 309,035 NewAmsterdam Pharma shares in Q2 2026, an estimated $10.2M.
NewAmsterdam Pharma made up ﹤0.01% of Jane Street's portfolio in Q2 2026, its #2354 holding.
Jane Street first reported a position in NewAmsterdam Pharma in Q4 2025 and has held it in 3 quarters since.
195 funds tracked by Wall St. Rank held NewAmsterdam Pharma as of Q2 2026.

Based on Jane Street's 13F filing for Q2 2026, filed 14 Aug 2026.