Seres Therapeutics MCRB Institutional Ownership

NASDAQ MCRB

$5.12 -0.16 (-3.03%)

As of: Sep 10, 2026 · 12:36 PM EDT

Institutions by Trading Activity

38 Institutions

Increased 17 44.7%

Unchanged 9 23.7%

Reduced 12 31.6%

Ownership Statistics

13F · as of 30 Jun, 2026

Institutional Ownership

23.75%

▼-0.32 pp QoQ

Shares Held by Institutions

2.31Mn

of 9.71Mn outstanding

▲+0.78% QoQ

Shares Outstanding

9.71Mn

7.40Mn held outside 13F filers

Institutional Investors

filed 13F for Jun 2026

▲+5 vs prior quarter

Net Shares Added (QoQ)

+17.95K

accumulated since last quarter

Value of Holdings

$13.19Mn

reported market value

Shares Owned by Institutions

Shares held % of outstanding

Latest —

Average ownership —

Peak ownership —

Shares Purchased/Sold by Institutions

Accumulated Distributed

Latest quarter —

Net over range —

Accumulating quarters —

Ownership Summary

Quarter ending 30 Jun, 2026

Seres Therapeutics, Inc. (NASDAQ:MCRB) appears in 38 institutional 13F filings for the quarter ending June 2026.

These investors collectively held 23.8% of Seres Therapeutics's outstanding shares in June 2026, down from 24.1% in March 2026.
Their total shares held in MCRB increased 0.78% quarter over quarter, and separately, investors owning Seres Therapeutics increased 15.15% from a year ago.
Activity in MCRB broke down as 17 buyers, 12 sellers, and 9 unchanged among 38 total holders.
Combined, these investors held 2.31Mn shares in MCRB for June 2026, up by 17.94K shares quarter on quarter, and up 326 shares year over year.
Flagship Pioneering, LLC leads ownership in MCRB with 1.16Mn shares as of June 30, 2026, equal to 11.91% of outstanding shares.
The biggest buyers of Seres Therapeutics for the quarter ending June 2026 included MARSHALL WACE, LLP (32.71K), Sixth Street Partners Management Company, L.P. (31.05K), XTX Topco Ltd (20.73K), Goldman Sachs Group Inc (15.23K), CITADEL ADVISORS LLC (10.5K).
The largest sellers of Seres Therapeutics for the quarter ending June 2026 were SUSQUEHANNA INTERNATIONAL GROUP, LLP (47.01K), AMERICAN CENTURY COMPANIES INC (34.0K), Vontobel Holding Ltd. (15.49K), Morgan Stanley (9.56K), UBS Group AG (6.55K).
Per Business Quant data, the top 10 holders of Seres Therapeutics for the quarter ending June 2026 are Flagship Pioneering, LLC (1.16Mn), VANGUARD CAPITAL MANAGEMENT LLC (287.78K), MARSHALL WACE, LLP (172.24K), Vontobel Holding Ltd. (122.98K), BlackRock, Inc. (111.0K), GEODE CAPITAL MANAGEMENT, LLC (79.97K), SUSQUEHANNA INTERNATIONAL GROUP, LLP (58.33K), VANGUARD FIDUCIARY TRUST CO (48.68K), State Street Corp (33.9K), Lion Point Capital, LP (31.57K).

Form 13F Holdings

38 Institutional Holders

Report period 30 Jun, 2026

Total shares held 2.31Mn

Of outstanding 23.75%

#	Institution	CIK	Shares Held	% of Outstanding	Change (QoQ)	Change (%)	Value (USD)
1	Flagship Pioneering, LLC	0001400240	1,155,850	11.91%	0	0.00%	$9.12Mn
2	VANGUARD CAPITAL MANAGEMENT LLC	0002100119	287,776	2.96%	▼6,367	-2.16%	$2.27Mn
3	MARSHALL WACE, LLP	0001318757	172,245	1.77%	▲32,706	+23.44%	$1.36Mn
4	Vontobel Holding Ltd.	0001588340	122,975	1.27%	▼15,493	-11.19%	$970.27K
5	BlackRock, Inc.	0002012383	111,000	1.14%	▲8,974	+8.80%	$875.79K
6	GEODE CAPITAL MANAGEMENT, LLC	0001214717	79,974	0.82%	▲5,139	+6.87%	$631.30K
7	SUSQUEHANNA INTERNATIONAL GROUP, LLP	0001446194	58,328	0.60%	▼47,011	-44.63%	$460.21K
8	VANGUARD FIDUCIARY TRUST CO	0000933478	48,685	0.50%	▲9,042	+22.81%	$384.13K
9	State Street Corp	0000093751	33,901	0.35%	0	0.00%	$267.48K
10	Lion Point Capital, LP	0001643354	31,570	0.33%	0	0.00%	$249.09K
11	CHARLES SCHWAB INVESTMENT MANAGEMENT INC	0000884546	31,049	0.32%	▼581	-1.84%	$244.98K
11	Sixth Street Partners Management Company, L.P.	0001812095	31,049	0.32%	▲31,049	0.00%	$244.98K
12	AMERICAN CENTURY COMPANIES INC	0000748054	28,313	0.29%	▼34,003	-54.57%	$223.39K
13	XTX Topco Ltd	0001828301	20,732	0.21%	▲20,732	0.00%	$163.58K
14	Goldman Sachs Group Inc	0000886982	15,229	0.16%	▲15,229	0.00%	$120.16K
15	Northern Trust Corp	0000073124	14,765	0.15%	0	0.00%	$116.50K
16	Invesco Ltd.	0000914208	12,974	0.13%	▼1,573	-10.81%	$102.37K
17	Morgan Stanley	0000895421	12,138	0.13%	▼9,562	-44.06%	$95.77K
18	CITADEL ADVISORS LLC	0001423053	10,504	0.11%	▲10,504	0.00%	$82.88K
19	SIMPLEX TRADING, LLC	0001488542	4,598	0.05%	▲1,528	+49.77%	$36.28K

Showing 1 to 20 of 38 holders