Flagship Pioneering, LLC

CAMBRIDGE, MA · CIK 1400240 · 13F filing filed 2026-08-14

Exempt reporting adviser since 2012 · limited liability company

Private funds29 · $13.4bn gross assets
Websiteflagshipventures.com
Form ADV · 2026-03-31SEC adviser record

$1.5bn reported value +32.6% vs Q1 2026

5positions

100.0%in top 10

0 new 0 added 0 reduced 0 sold out vs Q1 2026

This report includes the holdings of 2 other managers that share the investment decisions:

Afeyan Noubar – reports through this filing
Flagship Ventures Fund IV General Partner LLC – reports through this filing

Shares in two reports are counted once in each security's totals.

Holdings, Q2 2026

The small lines show how much was held over the last 4 quarters (adjusted for stock splits).

#	Security	Ticker	Shares	Value	% of portfolio	Change
1	GENERATE BIOMEDICINES INC COM SHS GENB	GENB	62,673,117	$1.1bn68.66%	68.66%	Unchanged
2	MODERNA INC COM MRNA	MRNA	4,632,149	$324.4m21.07%	21.07%	Unchanged
3	SANA BIOTECHNOLOGY INC COM SANA	SANA	25,001,856	$87.3m5.67%	5.67%	Unchanged
4	FOGHORN THERAPEUTICS INC COM FHTX	FHTX	12,674,120	$61.8m4.02%	4.02%	Unchanged
5	SERES THERAPEUTICS INC COM NEW MCRB	MCRB	1,155,850	$9.1m0.59%	0.59%	Unchanged

Stakes above 5%

Companies where this manager has reported owning more than 5% of a class of shares, on Schedule 13D (may seek influence) or 13G (passive): its latest filing for each, from 19 Dec 2024 on.

Company	Ticker	Stake	Change	Schedule	Last filed
GENERATE BIOMEDICINES INC GENB · 13G · filed 2026-05-15	GENB	48.9%≈ $1.1bn	new	13G	2026-05-15