Security key
81750R201
Seres Therapeutics, Inc. - COMMON STOCK (MCRB)
CUSIP: 81750R201
Q1 2026 13F Holders as of 31 Mar 2026
- Security type / class
- Equity / COMMON STOCK
- Total 13F shares
- 2,306,457
- Total 13F value
- $20,458,733
- Share change
- -146,091
- Put/Call ratio
- 219%
- SEC-reported price per share
- $8.87
- Number of holders
- 32
- Value change
- -$2,224,292
- Number of buys
- 11
- Number of sells
- 14
- Shares outstanding
- 8,667,871
Holder snapshot
7 signals
Open additional details 1 more signal available
Security identity
Names, identifiers, and filing context for this profile.
1 source field
Report period
Q1 2026
Institutions
32
Top holders
10
MCRB full security history
Ownership snapshot
Full 13F holder table
Previous quarter: Q4 2025
Seres Therapeutics, Inc. SEC filings
Seres Therapeutics, Inc. company facts
Broader feeds
Reporting periods
Holder history for CUSIP 81750R201
Recent filing periods:
Ownership snapshot
Top reported holders of MCRB - Seres Therapeutics, Inc. - COMMON STOCK (13F + 13D/G + 3/4/5)
Grouped by holder across the latest SEC ownership disclosures. Start with comparable ownership when available, then verify the linked 13F, 13D/G, or 3/4/5 evidence.
Comparable stake leader
FMR LLC
Disclosed value leader
Flagship Pioneering, LLC
Comparable rows
15/15
Latest evidence
31 Dec 2025
13D/G
13F
Lead comparable stake: 3.1%
13D/G row: FMR LLC
Showing 1-6 of 15 holder rows.
Quick read
FMR LLC leads the comparable SEC ownership view at 3.1%.
15 of 15 rows have a safely comparable ownership percentage. Use this as a filing-backed starting point, then open the detailed table for source links, reporting role, position value, share count, and filing date.
Open SEC evidence
Opens FMR LLC's linked filing trail.
Comparable ownership
Top 5
FMR LLC
3.1%
Flagship Pioneering, LLC
13%
VANGUARD GROUP INC
3.7%
SUSQUEHANNA INTERNATIONAL GROUP, LLP
2.1%
MARSHALL WACE, LLP
1.4%
Ownership % is shown only when SEC disclosures are safely comparable across share classes.
Detailed SEC evidence table Showing 1-6 of 15 holder rows
| Holder | Evidence | Ownership % | Position | 12M Net Δ | As of |
|---|---|---|---|---|---|
| FMR LLC |
13D/G
13F
Company
|
3.1%
|
$3,377,609
268,704 shares
|
-$2,827,043 | 30 Jun 2025 |
| Flagship Pioneering, LLC |
13F
Company
|
13%
|
$17,236,411
1,155,850 shares
|
— | 31 Dec 2025 |
| VANGUARD GROUP INC |
13F
Company
|
3.7%
|
$4,824,304
324,214 shares
|
— | 31 Dec 2025 |
| SUSQUEHANNA INTERNATIONAL GROUP, LLP |
13F
Company
|
2.1%
|
$2,677,344
179,929 shares
|
— | 31 Dec 2025 |
| MARSHALL WACE, LLP |
13F
Company
|
1.4%
|
$1,788,234
120,177 shares
|
— | 31 Dec 2025 |
| BlackRock, Inc. |
13F
Company
|
1.2%
|
$1,541,880
103,621 shares
|
— | 31 Dec 2025 |
How to read this table
Rows are grouped by holder and ranked first by SEC-reported ownership % when it is safely comparable, then by disclosed holdings value. — indicates unavailable or non-comparable values; "mixed-class rows" means the latest filing spans non-comparable classes.
13F holder rows
Institutional holders as of Q1 2026
Investor-level positions for this CUSIP, loaded as an interactive table.
Institutions
32
Shares
2,306,457
Rows available
32
| Investor | Option | Weight % | Change % | SEC-reported value | * Price | Shares | Share Change | Activity | Report Period |
|---|
* SEC-reported price is the security price as of the portfolio date and can indicate the last known price at which the security was still held. The marker flags a reported price that did not pass the local price check.
Compare Q1 2026 vs Q4 2025 Across Filers
Q4 2025 holders
35
Q1 2026 holders
32
Holder diff
-3
| Investor | Q4 2025 Shares | Q1 2026 Shares | Share Diff | Share Chg % | Q4 2025 value | Q1 2026 value | Value change | Value Chg % |
|---|
Trend: ostatnie 8 kwartałów (+ wybrane okresy porównania).
Quarterly Holders Trend
Quarterly Value Trend
Quarterly Shares Trend