Flagship Pioneering portfolio
Private equity or venture capitalPortfolio 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.
Flagship Pioneering reported a $1.5 bn portfolio of 5 positions to the SEC as of the end of Q2 2026. Its largest positions are GENB, MRNA, SANA.
Sections with a free account
What changed this quarter
No moves of 0.5 points of the portfolio or more.
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
- Generate BiomedicinesGENB68.7%
- ModernaMRNA21.1%
- Sana BiotechnologySANA5.7%
- Foghorn TherapeuticsFHTX4.0%
- Seres TherapeuticsMCRB0.6%
“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: 5
Q2 2026: 100%
Q2 2026: 0.0%
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.
How we classify it
Private equity or venture capital, per its Form ADV of Mar 31, 2026 (high confidence).
The data, as reported: FLAGSHIP PIONEERING, LLC (CRD 161864): Exempt reporting adviser under 2.B(1): advises venture capital funds only; 7.B private funds: 29 vc (gross assets $13.4 bn) · 13F: 99% of the portfolio was already held when the stock started trading
The type comes from a rule applied to that data. If it looks wrong, tell us.
Not counted as a concentrated manager: it is a private equity or venture firm; its stocks are usually holdings that went public. Its portfolio is shown all the same, but it is left out of manager counts, the consensus and the ranking. How this is decided
Managers of a similar size
A 13F portfolio value between a third and three times this one, whatever the type of filer. It is not a comparison of what they hold.
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