Flagship Pioneering, LLC
Clone Performance
Aug 2023–Aug 2026 · vs SPYHypothetical growth of buying every stock this filer reported holding, rebalancing on each filing and indexed to the same start. Option positions cannot be bought this way and are left out.
Estimate. 13F holdings are quarter-lagged, so the clone rebalances about 45 days after each period end — when the filing becomes public — and it excludes option and short positions. Returns use comparable raw closes and exclude dividends; a captured split can shorten the simulated window. It tracks 100% of reported value on average across 13 quarters. Past performance does not predict future results.
Portfolio Concentration
5 tracked positions · as of Jun 30, 2026 · Δ vs Mar 31, 2026Portfolio Trend
Sector Breakdown
As of Jun 30, 2026| Sector | % Portfolio | Value |
|---|---|---|
| Healthcare | 100.0% | $1,539,910,714 |
Last Quarter's Activity
Export CSVAdded To
Positions the filer increasedTrimmed
Positions the filer reducedNew Positions
Positions the filer opened this quarterSold Out
Positions the filer fully exited| Ticker | Company | Type | Shares | Value (USD) | % of Portfolio | History |
|---|---|---|---|---|---|---|
| GENB |
Generate Biomedicines, Inc.
Healthcare
|
Reduced | 62,673,117 | $1,057,295,483 | 68.66% | |
| MRNA |
Moderna, Inc.
Healthcare
|
Held | 4,632,149 | $324,389,393 | 21.07% | |
| SANA |
Sana Biotechnology, Inc.
Healthcare
|
Held | 25,001,856 | $87,256,477 | 5.67% | |
| FHTX |
Foghorn Therapeutics Inc.
Healthcare
|
Held | 12,674,120 | $61,849,705 | 4.02% | |
| MCRB |
Seres Therapeutics, Inc.
Healthcare
|
Held | 1,155,850 | $9,119,656 | 0.59% |
Covers the securities this platform tracks: U.S.-listed common stock and the put/call positions reported on it. A 13F can also report security types outside that coverage — preferred shares, bonds, warrants, untracked share classes — so the filing's own declared total can exceed the figures above. The source filing is linked at the top of this table.