MPM Bioimpact portfolio
Concentrated managerInvestment firmPortfolio as of Jun 30, 2026 (Q2 2026) · filed with the SEC on Aug 14, 2026 · data updated on Nov 5, 2026 · Q2 2026 13F (filing) ↗ · all its 13F filings ↗
A 13F shows the portfolio at quarter-end and is filed up to 45 days later: these are not real-time positions and they may have changed.
MPM Bioimpact reported a $1.6 bn portfolio of 37 positions to the SEC as of the end of Q2 2026. Its largest positions are CGEM, AKTS, LQDA. During the quarter it opened Ultragenyx Pharmaceutical and Bioage Labs and exited Agios Pharmaceuticals and Xenon Pharmaceuticals.
Sections with a free account
What it reported after the quarter end (Q2 2026)
The 13F shows the portfolio as of Jun 30, 2026. Since then MPM Bioimpact has filed these own trades with the SEC (Form 4, when it owns more than 10% of a company or holds a role in it) and stakes above 5% (13D and 13G). It is not everything it did: only what it must report before the next 13F.
What changed this quarter
43 positions with a change (7 new, 7 added to, 18 trimmed, 11 sold). 12 are listed here: those of 0.5 points of the portfolio or more (up to 12).
- Ultragenyx Pharmaceutical+2.9 ppof portfolioNew— → 2.9%
- Agios Pharmaceuticals−2.7 ppof portfolioSold out3.4% → —
- Bioage Labs+2.5 ppof portfolioNew— → 2.5%
- Cullinan Therapeutics+27%more sharesIncreased8.4% → 10.8%
- Xenon Pharmaceuticals−2.1 ppof portfolioSold out2.6% → —
- Evommune−2.0 ppof portfolioSold out2.6% → —
- Cytokinetics−2.0 ppof portfolioSold out2.5% → —
- Taysha Gene Therapies+1.9 ppof portfolioNew— → 1.9%
- Abivax+214%more sharesIncreased0.9% → 2.7%
- Zura Bio+1.6 ppof portfolioNew— → 1.6%
- DBV Technologies−30%fewer sharesReduced8.4% → 3.7%
- Corvus Pharmaceuticals−1.5 ppof portfolioSold out1.9% → —
The figure on the right: for positions added to or trimmed, the change in the number of shares (%); for new and sold ones, the points of the portfolio moved (pp). Below, the portfolio weight before → after. Traded weight: what it bought or sold, excluding price effects.
Top holdings
- Cullinan TherapeuticsCGEM10.8%
- Aktis OncologyAKTS9.5%
- LiquidiaLQDA6.7%
- Revolution MedicinesRVMD5.6%
- Corcept TherapeuticsCORT4.1%
- Edgewise TherapeuticsEWTX4.0%
- Travere TherapeuticsTVTX3.9%
- DBV TechnologiesDBVT3.7%
- Trevi TherapeuticsTRVI3.5%
- AlumisALMS3.5%
- uniQureQURE3.4%
- Ultragenyx PharmaceuticalRARE2.9%
- Relay TherapeuticsRLAY2.8%
- AbivaxABVX2.7%
- Dyne TherapeuticsDYN2.6%
“Since”: first quarter of the current run, unbroken until today. In the details, prices are the quarter-end prices of the quarters in which it added shares, per the 13F. The manager may have bought at any price within each quarter; the SEC only publishes the value at quarter end.
Portfolio by sector
- ● Health Care 100%
How its portfolio changed (8 quarters)
Q2 2026: 37
Q2 2026: 55%
Q2 2026: 19.0%
Traded turnover: the weight it bought plus the weight it sold in the quarter, divided by two, excluding price moves. The plain “turnover” in the header does include that effect. With a free account: the full history and sectors over time.
Stakes above 5% (13D/13G)
Companies where this filer reported holding 5% or more of the shares. It is the figure from its latest filing on each one; history since December 2024.
Similar managers by type and size
Same type of filer and a 13F portfolio value between a third and three times this one. It is not a comparison of what they hold.
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