Flagship Pioneering, LLC

All Holdings — 2025 Q4

AI Portfolio Summary
In 2025 Q4, Flagship Pioneering, LLC maintained a portfolio of 4 distinct positions.
PCA Score Concentration Risk
Risk ENB
Total Positions
4
Quarter
2025 Q4
Top Holding
MRNA (42.2%)
Top 10 Concentration
100.0%
Turnover Rate
23.4%
Sector HHI
0.18
Items per page:
1-4 of 4
Stock History Sector / Type Port % Prev % Rank / Prev Conviction Change % Change Influence Shares Mkt Value Avg Cost Price Held 1st Owned Source Source Date Date Reported
MRNA
Moderna Inc
Healthcare 42.16% 40.89% #1
Prev: #1
10.0 no change no change
P
S
4,632,149 $136,602,075 2018 Q4 13F Filing 2025-12-31 2026-02-14 (Est.)
SANA
Sana Biotechnol...
Healthcare 31.40% 30.33% #2
Prev: #2
10.0 no change no change
P
S
25,001,856 $101,757,555 2021 Q1 13F Filing 2025-12-31 2026-02-14 (Est.)
FHTX
Foghorn Therape...
Healthcare 21.12% 21.18% #3
Prev: #3
8.4 no change no change
P
S
12,674,120 $68,440,247 2020 Q4 13F Filing 2025-12-31 2026-02-14 (Est.)
MCRB
Seres Therapeut...
Healthcare 5.32% 7.60% #4
Prev: #4
2.1 no change no change
P
S
1,155,850 $17,236,411 2025 Q2 13F Filing 2025-12-31 2026-02-14 (Est.)
Showing 1-4 of 4 holdings

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