Seres Therapeutics

MCRB • NASDAQ

Seres Therapeutics is a biotechnology company in the healthcare sector on NASDAQ, led by Marella Thorell and Thomas J. DesRosier, with a market cap of $153.2M. As of Q3 2025, 24% of shares are held by 32 institutional investors, with Flagship Ventures Management, Inc. as the largest holder at 13.2%.

Co-Chief Executive Officers and Co-PresidentsMarella Thorell and Thomas J. DesRosier

Market Cap$153.2M

Biotechnology

Healthcare

Employees233.0

Websiteserestherapeutics.com

Country

United States of America

Overview

Overview of institutional ownership in MCRB as of Q3 2025 with a market cap of $168.4M

All Institutions

Institutions: 32
Value Held: $40.9M
Shares Held: 2.1M
Avg Position: $1.3M
Median Position: $151.9K

Hedge Funds

Hedge Funds: 4
Value Held: $2.2M
Shares Held: 114.0K
Avg Position: $548.2K
Median Position: $539.5K

Ownership Breakdown

Institutional (non-HF)

22.98%

$38.7M

Hedge Funds

1.3%

$2.2M

Retail & Other

75.72%

$127.5M

Based on market cap of $168.4M as of Q3 2025. Institutional (non-HF) excludes hedge funds to avoid double counting.

Biggest Investors

Institutions with the largest positions in MCRB as of Q3 2025

Institution	Key People	Position Value	Ownership	Owned Since	Total AUM (Long)
Flagship Ventures Management, Inc. Institution	Thomas Allen Goldsmith President	$22.2M 7.60% of portfolio	13.20% 1.2M shares	Q3 2016 Held for 9y 2m	$292.6M
VANGUARD GROUP INC Institution	Salim Ramji CEO	$6.0M 0.00% of portfolio	3.56% 311.9K shares	Q2 2015 Held for 10y 5m	$6.69T
Marshall Wace LLP Institution	Diana Lj Harrison President	$2.4M 0.00% of portfolio	1.43% 125.6K shares	Q2 2025 Held for 5 months	$90.3B
B BlackRock, Inc. Institution	-	$2.0M 0.00% of portfolio	1.17% 102.1K shares	Q2 2015 Held for 10y 5m	$5.67T
V Vontobel Holding Ltd. Institution	-	$1.9M 0.01% of portfolio	1.13% 98.5K shares	Q1 2023 Held for 2y 8m	$31.8B
GEODE CAPITAL MANAGEMENT LLC ETF Provider	David Kenneth Lane CEO	$1.6M 0.00% of portfolio	0.97% 85.0K shares	Q3 2015 Held for 10y 2m	$1.57T
SCHWAB CHARLES INVESTMENT MANAGEMENT INC Long Only Manager	Omar Aguilar Chavez CEO	$604.2K 0.00% of portfolio	0.36% 31.4K shares	Q3 2015 Held for 10y 2m	$620.51B
CITADEL ADVISORS LLC Hedge Fund•Multi-Strategy	Kenneth Cordele Griffin CEO	$594.2K 0.00% of portfolio	0.35% 30.9K shares	Q3 2016 Held for 9y 2m	$122.08B
STATE STREET CORP Institution	Ronald P. O'Hanley CEO	$572.0K 0.00% of portfolio	0.34% 29.7K shares	Q3 2015 Held for 10y 2m	$2.88T
Schonfeld Strategic Advisors LLC Hedge Fund•Multi-Strategy	Ryan Andrew Tolkin CEO	$556.8K 0.00% of portfolio	0.33% 28.9K shares	Q2 2024 Held for 1y 5m	$14.3B

Net Capital Flow

Institutional buying and selling activity for MCRB in Q3 2025

Traded: +$2.9M
Buyers: 21
Sellers: 15
Total Bought: +$4.1M
Total Sold: −$1.2M
Avg Position: $973.9K

Biggest Buyers

Institution	Net Bought	Current Position
Marshall Wace LLP Institution	+$657.9K +34.2K shares	$2.4M 125.6K shares
CITADEL ADVISORS LLC Hedge Fund•Multi-Strategy	+$594.2K +30.9K shares	$594.2K 30.9K shares
Schonfeld Strategic Advisors LLC Hedge Fund•Multi-Strategy	+$556.8K +28.9K shares	$556.8K 28.9K shares
J J. Goldman & Co LP Hedge Fund•Multi-Strategy	+$519.5K +27.0K shares	$519.5K 27.0K shares
VANGUARD GROUP INC Institution	+$380.8K +19.8K shares	$6.0M 311.9K shares
V Vontobel Holding Ltd. Institution	+$349.9K +18.2K shares	$1.9M 98.5K shares
MORGAN STANLEY RIA/Wealth	+$201.9K +10.5K shares	$352.7K 18.3K shares
Invesco Ltd. ETF Provider	+$200.9K +10.4K shares	$200.9K 10.4K shares
L Lion Point Capital, LP Hedge Fund•Event Driven	+$194.3K +10.1K shares	$522.1K 27.1K shares
BANK OF AMERICA CORP /DE/ Institution	+$99.2K +5.2K shares	$102.8K 5.3K shares

Biggest Sellers

Institution	Net Sold	Current Position
X XTX Topco Ltd Institution	−$249.1K −22.4K shares	Sold Off 0 shares
S Squarepoint Ops LLC Hedge Fund•Quant	−$232.3K −20.9K shares	Sold Off 0 shares
T TANG CAPITAL MANAGEMENT LLC Institution	−$154.7K −13.9K shares	Sold Off 0 shares
B BRIDGEWAY CAPITAL MANAGEMENT INC Long Only Manager	−$138.9K −12.5K shares	Sold Off 0 shares
SUSQUEHANNA INTERNATIONAL GROUP, LLP Private Equity	−$129.8K −11.7K shares	Sold Off 0 shares
GEODE CAPITAL MANAGEMENT LLC ETF Provider	−$127.4K −6.6K shares	$1.6M 85.0K shares
SCHWAB CHARLES INVESTMENT MANAGEMENT INC Long Only Manager	−$66.8K −3.5K shares	$604.2K 31.4K shares
NORTHERN TRUST CORP Institution	−$57.2K −3.0K shares	$232.8K 12.1K shares
G GROUP ONE TRADING, L.P. Institution	−$12.9K −1.2K shares	Sold Off 0 shares
Union Bankshares Corp Institution	−$4.6K −411.0 shares	Sold Off 0 shares

Entry and Exit Activity

Institutions that initiated new positions or completely exited MCRB in Q3 2025

New Positions: 3
New Value: $519.6K
Exited Positions: 10
Exited Value: $924.8K

New Positions

Institution	Position Value
J J. Goldman & Co LP Hedge Fund•Multi-Strategy	$519.5K 27.0K shares
Federation des caisses Desjardins du Quebec Fund of Funds	$58.0 3.0 shares
SRS Capital Advisors, Inc. RIA/Wealth	$38.0 2.0 shares

Exited Positions

Institution	Previous Position
X XTX Topco Ltd Institution	$249.1K 22.4K shares
S Squarepoint Ops LLC Hedge Fund•Quant	$232.3K 20.9K shares
T TANG CAPITAL MANAGEMENT LLC Institution	$154.7K 13.9K shares
B BRIDGEWAY CAPITAL MANAGEMENT INC Long Only Manager	$138.9K 12.5K shares
SUSQUEHANNA INTERNATIONAL GROUP, LLP Private Equity	$129.8K 11.7K shares
G GROUP ONE TRADING, L.P. Institution	$12.9K 1.2K shares
Union Bankshares Corp Institution	$4.6K 411.0 shares
T Tower Research Capital LLC Institution	$2.1K 185.0 shares
RAYMOND JAMES FINANCIAL INC RIA/Wealth	$623.0 56.0 shares
WHITTIER TRUST CO RIA/Wealth	$11.0 1.0 shares

Options Activity

Institutions with the largest Call and Put options positions in MCRB as of Q3 2025

Call Positions: 9
Call Value: $13.7M
Put Positions: 3
Put Value: $1.9M

Call Positions

Institution	Position Value
SUSQUEHANNA INTERNATIONAL GROUP, LLP Private Equity	$6.1M 3.2K contracts
Hudson Bay Capital Management LP Hedge Fund•Multi-Strategy	$2.4M 1.3K contracts
Caption Management, LLC Hedge Fund•Long/Short	$1.4M 750.0 contracts
J JANE STREET GROUP, LLC Institution	$1.3M 681.0 contracts
J J. Goldman & Co LP Hedge Fund•Multi-Strategy	$1.2M 619.0 contracts
CITADEL ADVISORS LLC Hedge Fund•Multi-Strategy	$577.4K 300.1 contracts
Centiva Capital, LP Hedge Fund•Multi-Strategy	$481.0K 250.0 contracts
B Belvedere Trading LLC Institution	$232.8K 121.0 contracts
W WOLVERINE TRADING, LLC Institution	- - contracts

Put Positions

Institution	Position Value
SUSQUEHANNA INTERNATIONAL GROUP, LLP Private Equity	$1.5M 766.0 contracts
CITADEL ADVISORS LLC Hedge Fund•Multi-Strategy	$468.1K 243.3 contracts
B Belvedere Trading LLC Institution	$1.9K 1.0 contracts

Most Committed Institutions

Institutions with MCRB as the highest % of their portfolio as of Q3 2025

Institution	Key People	Portfolio Weight	Ownership	Owned Since	Total AUM (Long)
Flagship Ventures Management, Inc. Institution	Thomas Allen Goldsmith President	7.60% $22.2M	13.20% 1.2M shares	Q3 2016 Held for 9y 2m	$292.6M
L Lion Point Capital, LP Hedge Fund•Event Driven	Carl Didric Marcus Cederholm CIO	2.97% $522.1K	0.31% 27.1K shares	Q3 2021 Held for 4y 2m	$17.6M
J J. Goldman & Co LP Hedge Fund•Multi-Strategy	Jay Glenn Goldman CEO	0.02% $519.5K	0.31% 27.0K shares	Q3 2025 Held for 2 months	$2.6B
V Vontobel Holding Ltd. Institution	-	0.01% $1.9M	1.13% 98.5K shares	Q1 2023 Held for 2y 8m	$31.8B
Schonfeld Strategic Advisors LLC Hedge Fund•Multi-Strategy	Ryan Andrew Tolkin CEO	0.00% $556.8K	0.33% 28.9K shares	Q2 2024 Held for 1y 5m	$14.3B
Marshall Wace LLP Institution	Diana Lj Harrison President	0.00% $2.4M	1.43% 125.6K shares	Q2 2025 Held for 5 months	$90.3B
S SBI Securities Co., Ltd. Institution	-	0.00% $67.0K	0.04% 3.5K shares	Q4 2024 Held for 11 months	$3.9B
S SIMPLEX TRADING, LLC Institution	-	0.00% $54.0K	0.03% 2.8K shares	Q3 2025 Held for 2 months	$4.1B
CITADEL ADVISORS LLC Hedge Fund•Multi-Strategy	Kenneth Cordele Griffin CEO	0.00% $594.2K	0.35% 30.9K shares	Q3 2016 Held for 9y 2m	$122.08B
U UMA Financial Services, Inc. RIA/Wealth	Jeffrey Dell Zesiger President	0.00% $2.7K	0.00% 142.0 shares	Q2 2025 Held for 5 months	$685.2M

Hedge Fund Spotlight

Discover hedge funds investing in MCRB

Lion Point Capital, LP

Hedge Fund • Event Driven

Portfolio ManagerCarl Didric Marcus Cederholm

Portfolio Value: $17.6M
Positions: 27
Last Reported: Q3 2025

Sector Allocation

Position in Seres Therapeutics

Market Value: $522.1K
Shares Held: 27.1K
Portfolio Weight: 2.97%
Owned Since: 2021-Q3

Top Holding	Sector	Market Value	Weight
1 Mineralys Therapeutics, Inc. MLYS	Biotechnology Healthcare	$1.5M	8.40%
2 Milestone Pharmaceuticals MIST	Biotechnology Healthcare	$1.3M	7.48%
3 Fennec Pharmaceuticals FENC	Biotechnology Healthcare	$1.2M	6.54%