Jane Street’s MBX Biosciences MBX Stock Holding History

Jane Street’s Portfolio MBX Stock Details MBX Fund Activity

Bought

Maintained

Sold

Quarter	Market Value	Status	Shares	Change in Stake	Trade Value	Portfolio Weight	Portfolio Position
2026 Q1	$597K	Buy	20,000 +3,500	+21%	+$119K	﹤0.01%	7635
2025 Q4	$520K	Buy	+16,500	New	+$400K	﹤0.01%	7596

Other funds holding MBX

FLSM

Frazier Life Sciences Management Palo Alto, California $3.89B AUM 201.1% 1-Year Est. Return

OrbiMed New York $5.05B AUM 125.28% 1-Year Est. Return

NMC

NEA Management Company Timonium, Maryland $1.76B AUM 223.33% 1-Year Est. Return

Wellington Management Group Boston, Massachusetts $535B AUM 26.23% 1-Year Est. Return

BlackRock New York $5.72T AUM 30.48% 1-Year Est. Return

Fidelity Investments Boston, Massachusetts $1.9T AUM 41.92% 1-Year Est. Return

DTC

Deep Track Capital Greenwich, Connecticut $6.12B AUM 144% 1-Year Est. Return

NVP Associates Menlo Park, California $176M AUM 208.78% 1-Year Est. Return

PCH

Polar Capital Holdings London, United Kingdom $28.2B AUM 115.26% 1-Year Est. Return

Braidwell Stamford, Connecticut $3B AUM 46.72% 1-Year Est. Return

Jane Street's MBX Position: Q1 2026 in Review

Jane Street sold out of MBX Biosciences (MBX) in Q1 2026, closing a stake of 86,581 shares — an estimated $2.94M sold.

Jane Street first reported a position in MBX in Q3 2024 and held it in 2 quarters. The position peaked at $2.73M in Q4 2025. 157 funds tracked by Wall St. Rank hold MBX as of Q1 2026.

Jane Street reported no remaining MBX Biosciences position as of Q1 2026 after selling out during the quarter.
Jane Street sold 86,581 MBX Biosciences shares in Q1 2026, an estimated $2.94M.
Jane Street first reported a position in MBX Biosciences in Q3 2024 and held it in 2 quarters.
Jane Street's MBX Biosciences position peaked at $2.73M in Q4 2025.
157 funds tracked by Wall St. Rank held MBX Biosciences as of Q1 2026.

Based on Jane Street's 13F filing for Q1 2026, filed 12 May 2026.