Flagship Pioneering Inc.

Portfolio Overview

Flagship Pioneering Inc. disclosed 5 positions worth $1.2B in its Form 13F-HR for Q1 2026, led by $GENB (Generate Biomedicines, Inc.) at 67.4% of the equity portfolio, followed by $MRNA and $SANA. During the quarter the fund opened 1 new position and exited 0 — including a new stake in $GENB. The portfolio is most concentrated in Healthcare (100.0% of disclosed assets). All figures are sourced directly from Flagship Pioneering Inc.’s Form 13F-HR filing with the SEC under CIK 1400240.

• 

  Generate Biomedicines, Inc.

  $GENB

  —

  Quality

  $783.4M62,673,117 sh
• 

  Moderna, Inc.

  $MRNA

  15.9#2,743

  Quality

  $235.3M4,632,149 sh
• 

  Sana Biotechnology, Inc.

  $SANA

  —

  Quality

  $72.0M25,001,856 sh
• 

  Foghorn Therapeutics Inc.

  $FHTX

  11.2

  Quality

  $60.6M12,674,120 sh
• 

  Seres Therapeutics, Inc.

  $MCRB

  29.3

  Quality

  $10.3M1,155,850 sh

Company	Quality	Value	Shares
Generate Biomedicines, Inc.$GENB	—	$783.4M	62,673,117
Moderna, Inc.$MRNA	15.9#2,743	$235.3M	4,632,149
Sana Biotechnology, Inc.$SANA	—	$72.0M	25,001,856
Foghorn Therapeutics Inc.$FHTX	11.2	$60.6M	12,674,120
Seres Therapeutics, Inc.$MCRB	29.3	$10.3M	1,155,850

Showing top 5 of 5 holdings.

Full Holdings — Flagship Pioneering Inc. (Q1 2026)

All 5 disclosed positions from the latest Form 13F-HR, with quarter-over-quarter share changes and 13F Pro quality scores. Sourced from SEC EDGAR.

#	Ticker	Company	Value	Weight	QoQ	Quality
1	$GENB	Generate Biomedicines, Inc.	$783.4M	67.4%	NEW	—
2	$MRNA	Moderna, Inc.	$235.3M	20.3%	+0%	15.9
3	$SANA	Sana Biotechnology, Inc.	$72.0M	6.2%	+0%	—
4	$FHTX	Foghorn Therapeutics Inc.	$60.6M	5.2%	+0%	11.2
5	$MCRB	Seres Therapeutics, Inc.	$10.3M	0.9%	+0%	29.3