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13F holdings · Q2 2026

Flagship Pioneering

Cambridge, MA · files as Flagship Pioneering, LLC
Holdings as of Jun 30, 2026Filed Aug 14, 2026Next filing due Nov 16, 2026CIK 1400240

Flagship Pioneering reported 5 stocks worth $1.5B in its 13F filing for Q2 2026, filed Aug 14, 2026. Its largest holdings are GENB (68.7%), MRNA (21.1%) and SANA (5.7%).

Reported value$1.5B+32.6% vs last quarter
Stocks held50 new · 0 sold out
Top 5 weight100.0%very concentrated
Turnover0%of the portfolio changed
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Holdings

#StockValueWeightSharesChangeShares, 8 qtrsHeld
1
GENB
Generate Biomedicines Inc
$1.1B68.7%62.7MNo change2 of 8
2
MRNA
Moderna Inc
$324M21.1%4.6MNo change8 of 8
3
SANA
Sana Biotechnology Inc
$87.3M5.7%25MNo change8 of 8
4
FHTX
Foghorn Therapeutics Inc
$61.8M4.0%12.7MNo change8 of 8
5
MCRB
Seres Therapeutics Inc
$9.1M0.6%1.2MNo change5 of 8

Positions at Jun 30, 2026, as reported. Change is against the fund's Q1 2026 filing; weight is the share of the fund's reported stocks.

Reported value

last 8 quarters
$592MQ3 '24
$334MQ4 '24
$236MQ1 '25
$268MQ2 '25
$293MQ3 '25
$324MQ4 '25
$1.2BQ1 '26
$1.5BQ2 '26

The value of the US stocks the fund reported, at quarter end prices. It moves with the market as well as with buying and selling.

Filings for Q2 2026

straight from the SEC
FiledFormQuarter
Aug 14, 202613F-HRQ2 2026SEC filing ↗

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Flagship Pioneering 13F FAQ

What does Flagship Pioneering own?

Flagship Pioneering reported 5 stocks worth $1.5B in its 13F filing for Q2 2026, filed Aug 14, 2026. Its largest holdings are GENB (68.7%), MRNA (21.1%) and SANA (5.7%). The table above lists every position in the filing (the top 10 without an account).

What did Flagship Pioneering buy and sell in Q2 2026?

Compared with Q1 2026: 0 new positions, 0 added to, 0 trimmed and 0 sold out.

When will Flagship Pioneering file its next 13F?

Holdings as of Sep 30, 2026 are due by Nov 16, 2026. The filing appears on this page within minutes of reaching the SEC.

How much is Flagship Pioneering's portfolio worth?

The Q2 2026 filing reports $1.5B in US stocks. That leaves out cash, bonds, short positions and most foreign holdings, so the fund's total assets are usually larger.

For informational and educational purposes only. Not investment advice, and not a recommendation to buy or sell any security. Holdings come from the fund's SEC Form 13F filings as reported and show positions at the end of the quarter, up to 45 days before the filing. The fund may have changed its positions since. A 13F leaves out short positions, cash, bonds and most foreign holdings. See all hedge fund holdings.