Jane Street’s Phathom Pharmaceuticals PHAT Stock Holding History

Jane Street’s Portfolio PHAT Stock Details PHAT Fund Activity

Bought

Maintained

Sold

Quarter	Market Value	Status	Shares	Change in Stake	Trade Value	Portfolio Weight	Portfolio Position
2026 Q2	$838K	Sell	77,200 -11,000	-12%	-$126K	﹤0.01%	6908
2026 Q1	$980K	Buy	88,200 +64,100	+266%	+$810K	﹤0.01%	6535
2025 Q4	$400K	Sell	24,100 -28,300	-54%	-$404K	﹤0.01%	8194
2025 Q3	$617K	Sell	52,400 -155,800	-75%	-$1.61M	﹤0.01%	7396
2025 Q2	$2M	Buy	208,200 +198,000	+1,941%	+$1.1M	﹤0.01%	4415
2025 Q1	$64K	Buy	+10,200	New	+$61.9K	﹤0.01%	8945
2023 Q4	–	Sell	-10,600	Closed	-$110K	–	9655
2023 Q3	$110K	Sell	10,600 -18,100	-63%	-$248K	﹤0.01%	7914
2023 Q2	$411K	Buy	+28,700	New	+$331K	﹤0.01%	6622

Other funds holding PHAT

FLSM

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

MVM

Medicxi Ventures Management St. Helier, Jersey $177M AUM 212.06% 1-Year Est. Return

BlackRock New York $6.73T AUM 46.02% 1-Year Est. Return

Invesco Atlanta, Georgia $1.26T AUM 61.52% 1-Year Est. Return

Carlyle Group Washington, District of Columbia $10B AUM 10.61% 1-Year Est. Return

Millennium Management New York $276B AUM 44.8% 1-Year Est. Return

Vanguard Capital Management Malvern, Pennsylvania $4.68T AUM

GKIM

GW&K Investment Management Boston, Massachusetts $12.8B AUM 48.82% 1-Year Est. Return

Franklin Resources San Mateo, California $462B AUM 39.16% 1-Year Est. Return

NMC

NEA Management Company Timonium, Maryland $1.59B AUM 234.06% 1-Year Est. Return

Jane Street's PHAT Position: Q2 2026 in Review

Jane Street opened a new position in Phathom Pharmaceuticals (PHAT) in Q2 2026: 212,706 shares worth $2.31M. The stake represents ﹤0.01% of the portfolio and ranks #4923 among its holdings. This is a return to the name: Jane Street previously reported a position in PHAT as recently as Q4 2025.

Jane Street first reported a position in PHAT in Q1 2021 and has held it in 14 quarters since. The position peaked at $6.38M in Q4 2025. 162 funds tracked by Wall St. Rank hold PHAT as of Q2 2026.

Jane Street held 212,706 shares of Phathom Pharmaceuticals worth $2.31M as of Q2 2026.
Phathom Pharmaceuticals was a new Jane Street position in Q2 2026.
Phathom Pharmaceuticals made up ﹤0.01% of Jane Street's portfolio in Q2 2026, its #4923 holding.
Jane Street first reported a position in Phathom Pharmaceuticals in Q1 2021 and has held it in 14 quarters since.
Jane Street's Phathom Pharmaceuticals position peaked at $6.38M in Q4 2025.
162 funds tracked by Wall St. Rank held Phathom Pharmaceuticals as of Q2 2026.

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