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Flagship Pioneering, LLC

Position in MCRB — Seres Therapeutics, Inc.

CIK 1400240 CAMBRIDGE, MA

Position in MCRB

as of Jun 30, 2026 · filed Aug 14, 2026
Position Value
$9,119,656
-$1,132,733 QoQ
Shares Held
1,155,850
0.0% QoQ
Ownership
11.6%
of shares outstanding
% of Portfolio
0.59%
of 13F equity value
Holder Rank
#1
of 36 holders
Holding Since
Mar 2020
26 quarters on record
Voting authority Sole 0% Shared 100% None 0%

Common Shares in MCRB Over Time

Shares Held

Position Value (USD)

Position in Biotechnology

Healthcare · as of Jun 30, 2026

Flagship Pioneering, LLC holds $1,539,910,714 across 5 Biotechnology names. MCRB ranks #5 (0.6% of the industry book) .

# Ticker Company Shares Value (USD) Open
5 MCRB
Seres Therapeutics, Inc.
This page
1,155,850 $9,119,656

All Filings in MCRB

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26 filing rows on record
Report Date Value (USD) Shares
2026-06-30 $9,119,656 1,155,850
2026-03-31 $10,252,389 1,155,850
2025-12-31 $17,199,047 1,155,850
2025-09-30 $22,238,553 1,155,850
2025-06-30 $12,841,492 1,155,850
2025-03-31 $16,181,931 23,117,045
2024-12-31 $19,210,263 23,117,045
2024-09-30 $21,868,723 23,117,045
2024-06-30 $16,736,740 23,117,045
2024-03-31 $17,892,592 23,117,045
2023-12-31 $32,363,862 23,117,045
2023-09-30 $55,018,566 23,117,045
2023-06-30 $110,730,645 23,117,045
2023-03-31 $131,073,644 23,117,045
2022-12-31 $129,455,451 23,117,045
2022-09-30 $148,411,426 23,117,045
2022-06-30 $49,319,290 14,378,802
2022-03-31 $102,377,069 14,378,802
2021-12-31 $119,775,419 14,378,802
2021-09-30 $100,076,460 14,378,802
2021-06-30 $342,934,426 14,378,802
2021-03-31 $302,137,103 14,673,973
2020-12-31 $359,512,338 14,673,973
2020-09-30 $610,696,638 21,571,764
2020-06-30 $102,681,595 21,571,764
2020-03-31 $77,011,197 21,571,764