MCRB Seres Therapeutics, Inc.

NASDAQ
$4.56

Seres Therapeutics, Inc. (MCRB) Institutional Ownership

What the institutions did with MCRB last quarter, from their 13F filings. Counting managers rather than shares is the point: a single index fund adding to a position tells you far less than four hundred separate managers all deciding to. Positions as reported for the quarter ended June 30, 2026.

Managers reporting
41
filed a 13F this quarter
Managers holding
36
+3 on the quarter
Buyers
15
8 opened new
Sellers
17
5 sold out entirely
Buyer share
46.9%
of managers who traded it
Breadth
-6.3
net buyers, as a share of those trading

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Largest holders

Manager Shares % of reported
Flagship Pioneering, LLC 1.2M 50.8%
VANGUARD CAPITAL MANAGEMENT LLC 287.8K 12.7%
MARSHALL WACE, LLP 172.2K 7.6%
Vontobel Holding Ltd. 123.0K 5.4%
BlackRock, Inc. 111.0K 4.9%
GEODE CAPITAL MANAGEMENT, LLC 80.0K 3.5%
SUSQUEHANNA INTERNATIONAL GROUP, LLP 58.3K 2.6%
VANGUARD FIDUCIARY TRUST CO 48.7K 2.1%
STATE STREET CORP 33.9K 1.5%
Lion Point Capital, LP 31.6K 1.4%
CHARLES SCHWAB INVESTMENT MANAGEMENT INC 31.0K 1.4%
AMERICAN CENTURY COMPANIES INC 28.3K 1.2%
XTX Topco Ltd 20.7K 0.9%
GOLDMAN SACHS GROUP INC 15.2K 0.7%
NORTHERN TRUST CORP 14.8K 0.6%
Invesco Ltd. 13.0K 0.6%
MORGAN STANLEY 12.1K 0.5%
CITADEL ADVISORS LLC 10.5K 0.5%
SIMPLEX TRADING, LLC 4.6K 0.2%
SBI Securities Co., Ltd. 4.2K 0.2%
Integrated Wealth Concepts LLC 4.0K 0.2%
GROUP ONE TRADING LLC 3.7K 0.2%
JPMORGAN CHASE & CO 3.6K 0.2%
Vanguard Global Advisers, LLC 2.0K 0.1%
FMR LLC 1.5K 0.1%

Largest changes

Manager Action Previous Current Change
SUSQUEHANNA INTERNATIONAL GROUP, LLP Reduced 105.3K 58.3K -47.0K
AMERICAN CENTURY COMPANIES INC Reduced 62.3K 28.3K -34.0K
MARSHALL WACE, LLP Increased 139.5K 172.2K +32.7K
XTX Topco Ltd New 0 20.7K +20.7K
TWO SIGMA INVESTMENTS, LP Sold Out 18.8K 0 -18.8K
Vontobel Holding Ltd. Reduced 138.5K 123.0K -15.5K
GOLDMAN SACHS GROUP INC New 0 15.2K +15.2K
CITADEL ADVISORS LLC New 0 10.5K +10.5K
MORGAN STANLEY Reduced 21.7K 12.1K -9.6K
VANGUARD FIDUCIARY TRUST CO Increased 39.6K 48.7K +9.0K
BlackRock, Inc. Increased 102.0K 111.0K +9.0K
UBS Group AG Reduced 7.0K 484 -6.5K
VANGUARD CAPITAL MANAGEMENT LLC Reduced 294.1K 287.8K -6.4K
BARCLAYS PLC Reduced 6.5K 167 -6.3K
GEODE CAPITAL MANAGEMENT, LLC Increased 74.8K 80.0K +5.1K
Integrated Wealth Concepts LLC New 0 4.0K +4.0K
JPMORGAN CHASE & CO New 0 3.6K +3.6K
GROUP ONE TRADING LLC Increased 824 3.7K +2.9K
Invesco Ltd. Reduced 14.5K 13.0K -1.6K
SIMPLEX TRADING, LLC Increased 3.1K 4.6K +1.5K
SBI Securities Co., Ltd. Increased 3.5K 4.2K +700
CHARLES SCHWAB INVESTMENT MANAGEMENT INC Reduced 31.6K 31.0K -581
Tower Research Capital LLC (TRC) Reduced 794 316 -478
FMR LLC Reduced 1.8K 1.5K -224
Physician Wealth Advisors, Inc. Sold Out 142 0 -142

13F filings are due 45 days after quarter end and cover long positions in U.S.-listed equities only, so this is a lagged and partial picture: shorts, bonds and foreign listings never appear. Options positions are excluded here rather than folded into the share counts. Political ownership is coming.