Phathom Pharmaceuticals, Inc. (PHAT) Institutional Ownership

Ownership Summary

A total of 133 institutions have reported a stake in Phathom Pharmaceuticals, Inc. (NASDAQ:PHAT) as of September 2025, according to recent 13F filings with the SEC.

• These investors collectively held 89.3% of the company's total shares outstanding in September 2025, up from 84.1% in June 2025.
• In percentage terms, this reflects as a holdings change of 7.04% quarter on quarter, and an increase of 0.76% year over year.
• The latest 13F cycle for Phathom Pharmaceuticals reveals that of 133 total investors, 64 funds grew their exposure, whereas 35 reduced theirs and 34 made no changes.
• The aggregate institutional position in Phathom Pharmaceuticals now stands at 63.34Mn shares as of September 2025, after investors increased their holdings (up by 4.16Mn shares quarter on quarter which is down 9.16Mn shares year over year).
• As of September 30, 2025, Frazier Life Sciences Management, L.P. held Phathom Pharmaceuticals's largest shareholding position with over 12.47Mn shares, representing 17.57% of total outstanding shares.
• Among the most significant buyers of Phathom Pharmaceuticals during September 2025 were MILLENNIUM MANAGEMENT LLC (2.83Mn), Catalio Capital Management, LP (456.23K), AIGH Capital Management LLC (429.00K), VANGUARD GROUP INC (428.26K), SummitTX Capital, L.P. (385.97K).
• Leading sellers of Phathom Pharmaceuticals stock in September 2025 included Avidity Partners Management LP (758.50K), CITIGROUP INC (503.61K), Propel Bio Management, LLC (370.00K), Trexquant Investment LP (320.57K), 683 Capital Management, LLC (284.62K).
• The top 10 institutional holders of Phathom Pharmaceuticals for the quarter ending September 2025 included Frazier Life Sciences Management, L.P. (12.47Mn), Medicxi Ventures Management (Jersey) Ltd (7.46Mn), MILLENNIUM MANAGEMENT LLC (5.08Mn), Invesco Ltd. (3.86Mn), Carlyle Group Inc. (3.50Mn), BlackRock, Inc. (3.40Mn), VANGUARD GROUP INC (3.22Mn), Ensign Peak Advisors, Inc (2.50Mn), NEA Management Company, LLC (1.96Mn), 683 Capital Management, LLC (1.82Mn).