EcoR1 Capital’s Phathom Pharmaceuticals PHAT Stock Holding History

EcoR1 Capital’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	$6.78M	Hold	625,000	–	–	0.33%	25
2026 Q1	$6.94M	Buy	+625,000	New	+$7.89M	0.29%	23
2024 Q1	–	Sell	-198,480	Closed	-$1.81M	–	63
2023 Q4	$1.81M	Sell	198,480 -501,520	-72%	-$4.32M	0.05%	46
2023 Q3	$7.26M	Hold	700,000	–	–	0.24%	37
2023 Q2	$10M	Buy	+700,000	New	+$8.07M	0.25%	34

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

EcoR1 Capital's PHAT Position: Q2 2026 in Review

EcoR1 Capital held its Phathom Pharmaceuticals (PHAT) position steady in Q2 2026 at 625,000 shares worth $6.78M. The position accounts for 0.33% of the portfolio, ranked #25.

EcoR1 Capital first reported a position in PHAT in Q2 2023 and has held it in 5 quarters since. The position peaked at $10M in Q2 2023. 162 funds tracked by Wall St. Rank hold PHAT as of Q2 2026.

EcoR1 Capital held 625,000 shares of Phathom Pharmaceuticals worth $6.78M as of Q2 2026.
EcoR1 Capital left its Phathom Pharmaceuticals share count unchanged in Q2 2026.
Phathom Pharmaceuticals made up 0.33% of EcoR1 Capital's portfolio in Q2 2026, its #25 holding.
EcoR1 Capital first reported a position in Phathom Pharmaceuticals in Q2 2023 and has held it in 5 quarters since.
EcoR1 Capital's Phathom Pharmaceuticals position peaked at $10M in Q2 2023.
162 funds tracked by Wall St. Rank held Phathom Pharmaceuticals as of Q2 2026.

Based on EcoR1 Capital's 13F filing for Q2 2026, filed 14 Aug 2026.