Security Snapshot

Seres Therapeutics, Inc. - COMMON STOCK (MCRB) Institutional Ownership

CUSIP: 81750R201

13F Institutional Holders and Ownership History from Q1 2025 to Q3 2026

13F reference period

Q2 2026

Institutions Reporting

34

Shares (Excl. Options)

2.27MFull value: 2,270,367 · shares · 30 Jun 2026

Price

$7.89

The headline uses the Q2 2026 reference period after its reporting deadline. Available reports may still be incomplete or amended. Newer periods in the history table contain incoming reports and may be incomplete.

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Security type / class
Equity / COMMON STOCK
Symbol
MCRB on Nasdaq
All holders as of 30 Jun 2026
Q2 2026
Total 13F shares
2,270,367
Latest holder snapshot 5 signals
Total 13F value
$17,913,145
Portfolio coverage rank
0%
Share change
-36,090
Value change
-$303,903
Number of holders
34
Issuer context Names, identifiers, and filing context for this profile. 3 identity fields
Shares outstanding
8,667,871
SEC-reported price per share
$2.93
Insider filing price
$2.93
13F Shares, Excluding Options vs Price
13F Value, Excluding Options
Total Investors
Filing notes and source

Key facts

  • MCRB - Seres Therapeutics, Inc. - COMMON STOCK is tracked under CUSIP 81750R201.
  • 34 institutions reported positions in Q2 2026.
  • 1 significant owner is listed from Schedule 13D/13G reporting.

Change

  • Holder count moved from 32 to 34 between Q1 2026 and Q2 2026.
  • SEC-reported value moved from
    $20.46MFull value: $20,458,733 · USD · 31 Mar 2026
    to
    $17.91MFull value: $17,913,145 · USD · 30 Jun 2026
    .

Research use

  • You can quickly see who holds this security, then open quarter and manager detail pages for full evidence.
  • 13F and Schedule 13D/13G sections are kept together so you can cross-check institutional and beneficial ownership context.

Evidence

Source: SEC Form 13F

Latest holder context comes from 34 institutions filings for Q2 2026.

Open SEC evidence

Security key

81750R201

13F reference period

Q2 2026

13F holders

34

13D/G owners

1

CIK / CUSIP context first

Open Q2 2026 holders MCRB full holder history Seres Therapeutics, Inc. SEC filings Seres Therapeutics, Inc. company facts Seres Therapeutics, Inc. insider transactions

Broader feeds

Latest 13F filings Latest 13D/G filings All securities

13D/G owners

Significant owners

Large-stake holder rows connected to Schedule 13D/G evidence.

Rows
1
Security
MCRB
Filer Ownership Change % Holdings Value Net Change Nb Shares Change % Reporting Name Report Period
FMR LLC 3.1% -43% $3,377,609 -$2,827,043 268,704 -46% FMR LLC 30 Jun 2025
As of 30 Jun 2026, 34 institutional investors reported holding
2.27MFull value: 2,270,367 · shares · 30 Jun 2026
shares of Seres Therapeutics, Inc. - COMMON STOCK (MCRB). This represents 26% of the company’s total
8.67MFull value: 8,667,871 · shares · Stored outstanding share count
outstanding shares.

13F concentration

Top 25 institutional shareholders

Largest 13F positions for this security by reported shares and value.

Top holder share
26%
Institution Ownership % Shares Held Share Change % Portfolio % Holdings Value
Flagship Pioneering, LLC 13% 1,155,850 0% 0.59% $9,119,658
VANGUARD CAPITAL MANAGEMENT LLC 3.3% 287,776 -2.2% 0% $2,270,553
MARSHALL WACE, LLP 2% 172,245 +23% 0% $1,359,016
Vontobel Holding Ltd. 1.4% 122,975 -11% 0% $970,273
BlackRock, Inc. 1.3% 111,000 +8.8% 0% $875,790
GEODE CAPITAL MANAGEMENT, LLC 0.92% 79,974 +6.9% 0% $631,301
SUSQUEHANNA INTERNATIONAL GROUP, LLP 0.67% 58,328 -45% 0% $460,208
VANGUARD FIDUCIARY TRUST CO 0.56% 48,685 +23% 0% $384,125
STATE STREET CORP 0.39% 33,901 0% 0% $267,479
Lion Point Capital, LP 0.36% 31,570 0% 1.2% $249,087
CHARLES SCHWAB INVESTMENT MANAGEMENT INC 0.36% 31,049 -1.8% 0% $244,977
AMERICAN CENTURY COMPANIES INC 0.33% 28,313 -55% 0% $223,390
XTX Topco Ltd 0.24% 20,732 0% $163,575
GOLDMAN SACHS GROUP INC 0.18% 15,229 0% $120,157
NORTHERN TRUST CORP 0.17% 14,765 0% 0% $116,496
Invesco Ltd. 0.15% 12,974 -11% 0% $102,365
MORGAN STANLEY 0.14% 12,138 -44% 0% $95,769
CITADEL ADVISORS LLC 0.12% 10,504 0% $82,877
SIMPLEX TRADING, LLC 0.05% 4,598 +50% 0% $36,278
SBI Securities Co., Ltd. 0.05% 4,182 +20% 0% $32,996
GROUP ONE TRADING LLC 0.04% 3,714 +351% 0% $29,303
JPMORGAN CHASE & CO 0.04% 3,636 0% $28,325
Vanguard Global Advisers, LLC 0.02% 1,975 0% 0% $15,583
FMR LLC 0.02% 1,528 -13% 0% $12,056
Rachor Investment Advisory Services, LLC 0.02% 1,477 0% 0.01% $11,654

Quarter history

Institutional holders across reporting periods

Holder count, reported shares/value, and median price by quarter.

Periods
7
Headline period
Q2 2026
Rows shown
1-7 of 7
Period 13F Shares, Excl. Options Value, Excl. Options Value Change Price (Median) Investors
2026 Q3 133,164 $446,099 +$20,124 $3.35 3
2026 Q2 2,270,367 $17,913,145 -$303,903 $7.89 34
2026 Q1 2,306,457 $20,458,733 -$2,224,292 $8.87 32
2025 Q4 2,441,565 $36,368,373 +$4,536,402 $14.88 35
2025 Q3 2,125,842 $40,902,370 -$2,393,659 $19.24 32
2025 Q2 2,284,946 $25,385,817 +$24,555,434 $11.11 33
2025 Q1 145,407 $101,799 +$101,799 $0.70 4
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