Jane Street’s Disc Medicine IRON Stock Holding History

Jane Street’s Portfolio IRON Stock Details IRON Fund Activity

Bought

Maintained

Sold

Quarter	Market Value	Status	Shares	Change in Stake	Trade Value	Portfolio Weight	Portfolio Position
2025 Q4	–	Sell	-21,274	Closed	-$1.8M	–	11752
2025 Q3	$1.41M	Buy	+21,274	New	+$1.27M	﹤0.01%	5602
2025 Q1	–	Sell	-21,203	Closed	-$1.34M	–	9996
2024 Q4	$1.34M	Sell	21,203 -3,528	-14%	-$204K	﹤0.01%	4849
2024 Q3	$1.22M	Sell	24,731 -7,680	-24%	-$361K	﹤0.01%	5490
2024 Q2	$1.46M	Sell	32,411 -8,405	-21%	-$286K	﹤0.01%	5060
2024 Q1	$2.54M	Buy	40,816 +19,971	+96%	+$1.29M	﹤0.01%	3703
2023 Q4	$1.2M	Buy	20,845 +10,196	+96%	+$522K	﹤0.01%	5229
2023 Q3	$500K	Buy	+10,649	New	+$533K	﹤0.01%	6303
2023 Q2	–	Sell	-19,252	Closed	-$408K	–	9119
2023 Q1	$408K	Buy	+19,252	New	+$429K	﹤0.01%	6678
2022 Q1	–	Sell	-1,245	Closed	-$109K	–	10659
2021 Q4	$109K	Buy	+1,245	New	+$122K	﹤0.01%	9200

Other funds holding IRON

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

RCM

RA Capital Management Boston, Massachusetts $9.44B AUM 157.3% 1-Year Est. Return

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

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

State Street Boston, Massachusetts $2.9T AUM 29.55% 1-Year Est. Return

T. Rowe Price Associates Baltimore, Maryland $865B AUM 30.76% 1-Year Est. Return

AVLSA

Atlas Venture Life Science Advisors Cambridge, Massachusetts $790M AUM 223.66% 1-Year Est. Return

VCM

Vanguard Capital Management Malvern, Pennsylvania $4.04T AUM

FLSM

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

TCM

TCG Crossover Management Palo Alto, California $3.5B AUM 1,165.83% 1-Year Est. Return

Jane Street's IRON Position: Q4 2025 in Review

Jane Street sold out of Disc Medicine (IRON) in Q4 2025, closing a stake of 21,274 shares — an estimated $1.8M sold.

Jane Street first reported a position in IRON in Q4 2021 and held it in 9 quarters. The position peaked at $2.54M in Q1 2024. 196 funds tracked by Wall St. Rank hold IRON as of Q4 2025.

Jane Street reported no remaining Disc Medicine position as of Q4 2025 after selling out during the quarter.
Jane Street sold 21,274 Disc Medicine shares in Q4 2025, an estimated $1.8M.
Jane Street first reported a position in Disc Medicine in Q4 2021 and held it in 9 quarters.
Jane Street's Disc Medicine position peaked at $2.54M in Q1 2024.
196 funds tracked by Wall St. Rank held Disc Medicine as of Q4 2025.

Based on Jane Street's 13F filing for Q4 2025, filed 12 Feb 2026.