Phathom Pharmaceuticals, Inc. (PHAT) Institutional Ownership

Ownership Summary

The institutional landscape for Phathom Pharmaceuticals, Inc. (NASDAQ:PHAT) includes 164 filers as of the latest reporting cycle ending December 2025.

• The percentage of Phathom Pharmaceuticals owned by institutions changed from 86.6% in September 2025 to 74.3% in December 2025, marking a slight down trend.
• The company experienced a -0.51% quarterly change in institutional shares held, alongside an increase of 14.69% in total owners annually.
• During the quarter, 93 institutions bought more Phathom Pharmaceuticals shares, 47 sold shares, and 24 of the 164 total investors held their position steady.
• This class of investors decreased its holdings in Phathom Pharmaceuticals to 54.32Mn shares for the 13F-cycle ending December 2025, down by 278.23K shares quarter on quarter, and down 12.64Mn shares year over year.
• With 12.47Mn shares, Frazier Life Sciences Management, L.P. commands the largest institutional position in Phathom Pharmaceuticals as of December 31, 2025, equating to 17.05% of the company.
• Among the most significant buyers of Phathom Pharmaceuticals during December 2025 were Divisadero Street Capital Management, LP (662.31K), SUSQUEHANNA INTERNATIONAL GROUP, LLP (394.89K), NEXT CENTURY GROWTH INVESTORS LLC (393.77K), D. E. Shaw & Co., Inc. (261.07K), JANE STREET GROUP, LLC (249.21K).
• Leading sellers of Phathom Pharmaceuticals stock in December 2025 included MILLENNIUM MANAGEMENT LLC (3.00Mn), Caption Management, LLC (513.70K), Catalio Capital Management, LP (429.52K), AMERIPRISE FINANCIAL INC (368.85K), WASATCH ADVISORS LP (205.55K).
• The top 10 institutional holders of Phathom Pharmaceuticals for the quarter ending December 2025 included Frazier Life Sciences Management, L.P. (12.47Mn), Medicxi Ventures Management (Jersey) Ltd (7.46Mn), BlackRock, Inc. (3.56Mn), Carlyle Group Inc. (3.50Mn), VANGUARD GROUP INC (3.18Mn), MILLENNIUM MANAGEMENT LLC (2.08Mn), NEA Management Company, LLC (1.96Mn), 683 Capital Management, LLC (1.78Mn), WASATCH ADVISORS LP (1.33Mn), GW&K Investment Management, LLC (1.31Mn).