MBX Biosciences MBX Institutional Ownership

Updated Oct 11, 2026

MBX Biosciences, Inc. (NASDAQ:MBX) had 172 institutional holders reporting a position on Form 13F for the quarter ended June 30, 2026.

• Total shares held in MBX Biosciences rose 5.60% versus Q1 2026, while the number of holders rose 100.00% versus Q2 2025.
• Among the 172 holders of MBX Biosciences, 101 added to their positions, 50 reduced their stakes and 21 left their positions unchanged.
• In total, institutional investors held 55.48Mn shares of MBX Biosciences at the end of Q2 2026, up 2.94Mn from the prior quarter and up 18.67Mn from a year earlier.
• As of June 30, 2026, Frazier Life Sciences Management, L.P. held the largest stake in MBX Biosciences with 6.65Mn shares.
• The largest position increases in MBX for Q2 2026 were by FMR LLC (+2.39Mn shares), Wellington Management Group LLP (+1.79Mn shares), BlackRock, Inc. (+382.27K shares), Marshall Wace, LLP (+339.18K shares) and Soleus Capital Management, L.P. (+336.38K shares).
• Holders that trimmed the most shares of MBX Biosciences in Q2 2026 while keeping a position were Deep Track Capital, LP (-1.02Mn shares), Braidwell LP (-781.59K shares), Caligan Partners LP (-648.59K shares), Cormorant Asset Management, LP (-570K shares) and EcoR1 Capital, LLC (-388.5K shares).
• Business Quant data shows the 10 biggest positions in MBX Biosciences as of Q2 2026 were held by Frazier Life Sciences Management, L.P. (6.65Mn shares), FMR LLC (5.32Mn shares), Wellington Management Group LLP (4.98Mn shares), NEA Management Company, LLC (3.61Mn shares), OrbiMed Advisors LLC (3.43Mn shares), BlackRock, Inc. (3.32Mn shares), Paradigm Biocapital Advisors LP (2.51Mn shares), NVP Associates, LLC (2.14Mn shares), Deep Track Capital, LP (1.73Mn shares) and Polar Capital Holdings PLC (1.61Mn shares).