Flagship Pioneering, LLC holds a concentrated book of 5 stocks worth $1.2B as of Q1 2026 (disclosed May 15, 2026, a ~45-day 13F lag). This quarter they opened Generate Biomedicines Inc. Their largest long position is Generate Biomedicines Inc at 67% of the equity book.
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This fund page is the Follow view. The Build view lets your agent pull holdings, quarter changes, overlap, and source filings through API or MCP.
curl -H "Authorization: Bearer YOUR_API_KEY" \ "https://arkolith.com/api/v1/funds/1400240/holdings"
Use Arkolith to show Flagship Pioneering, LLC's latest holdings, largest changes, and filing provenance.
Top-heavy: concentrated book
Share of the disclosed book in its largest positions. A higher top-5 share means a more concentrated, higher-conviction portfolio.
100% mapped to company sectors
Direct operating-company sectors from our SIC-based security master. ETF/fund and unclassified holdings stay visible separately; this is not ETF look-through exposure.
Estimated $ traded · quarter-end prices, no cost basis
No trims or exits this quarter.
Other tracked managers holding the same core names as Flagship Pioneering, LLC
| Manager / fund | Shared names | Their $ in those |
|---|---|---|
| FMR LLC | 5 / 5 | $2.5B |
| VANGUARD CAPITAL MANAGEMENT LLC | 5 / 5 | $1.2B |
| GEODE CAPITAL MANAGEMENT, LLC | 5 / 5 | $496.7M |
| MORGAN STANLEY | 5 / 5 | $439.4M |
| GOLDMAN SACHS GROUP INC | 5 / 5 | $347.4M |
| UBS Group AG | 5 / 5 | $232.7M |
| VANGUARD FIDUCIARY TRUST CO | 5 / 5 | $104.7M |
| BANK OF AMERICA CORP /DE/ | 5 / 5 | $59.3M |
Ranked by how many of Flagship Pioneering, LLC's top 5 disclosed names each fund also holds: a cross-fund conviction signal from the latest 13F of every tracked manager.
Bars show each stock's share of the portfolio. Click a row for its position history.
| # | Security | Value | Shares | % Port | Last move | History |
|---|---|---|---|---|---|---|
| 1 | Generate Biomedicines Inc COM SHS | $783.4M | 62.67M | 67.4% | ▲New New position | |
| 2 | Moderna Inc COM | $235.3M | 4.63M | 20.3% | —Held | |
| 3 | Sana Biotechnology Inc COM | $72.0M | 25.00M | 6.2% | —Held | |
| 4 | Foghorn Therapeutics Inc COM | $60.6M | 12.67M | 5.2% | —Held | |
| 5 | Seres Therapeutics Inc COM NEW | $10.3M | 1.16M | 0.9% | —Held |
As-of date vs the date the SEC received each filing
Holdings from SEC EDGAR 13F-HR filings, updated quarterly ~45 days after quarter-end. Public domain. The book and weighting are long equity only; disclosed put/call options are listed separately and excluded from those totals. Price-derived performance is withheld until the price-source policy and freshness gate are green.