Seres Therapeutics, Inc. - MCRB
Detailed investor-level table based on 13F positions.
Methodology:
Market value and % of portfolio use SEC reported VALUE ($000).
For PUT/CALL positions this reflects reported underlying exposure, not premium cash paid/received.
Details.
Rows: 0
| Investor | History | Status | Shares held | Market value ($000) | % of portfolio | Previous % | Rank | Change in shares | % change in shares | Source | Date reported |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Flagship Pioneering, LLC | History | No change | 1,155,850 | 10,252 | 0.88% | 5.32% | 1 | 0 | 0.0% | Q1 2026 | May 15, 2026 |
| VANGUARD GROUP INC | History | No change | 324,214 | 4,824 | 0.0% | 0.0% | 2 | 0 | 0.0% | Q4 2025 | Jan 29, 2026 |
| VANGUARD CAPITAL MANAGEMENT LLC | History | New | 294,143 | 2,609 | 0.0% | — | 3 | +294,143 | New | Q1 2026 | May 15, 2026 |
| SUSQUEHANNA INTERNATIONAL GROUP, LLP | History | Reduced | 226,939 | 2,012 | 0.0% | 0.0% | 4 | -105,890 | -31.82% | Q1 2026 | May 15, 2026 |
| MARSHALL WACE, LLP | History | Added to | 139,539 | 1,237 | 0.0% | 0.0% | 5 | +19,362 | 16.11% | Q1 2026 | May 14, 2026 |
| Vontobel Holding Ltd. | History | Added to | 138,468 | 1,228 | 0.0% | 0.0% | 6 | +35,234 | 34.13% | Q1 2026 | May 08, 2026 |
| BlackRock, Inc. | History | Reduced | 102,026 | 904 | 0.0% | 0.0% | 7 | -1,595 | -1.54% | Q1 2026 | May 13, 2026 |
| GEODE CAPITAL MANAGEMENT, LLC | History | Reduced | 74,835 | 664 | 0.0% | 0.0% | 8 | -11,307 | -13.13% | Q1 2026 | May 15, 2026 |
| AMERICAN CENTURY COMPANIES INC | History | Added to | 62,316 | 552 | 0.0% | 0.0% | 9 | +46,045 | 282.99% | Q1 2026 | May 15, 2026 |
| CITADEL ADVISORS LLC | History | Reduced | 59,500 | 527 | 0.0% | 0.0% | 10 | -14,748 | -19.86% | Q1 2026 | May 15, 2026 |
| VANGUARD FIDUCIARY TRUST CO | History | New | 39,643 | 351 | 0.0% | — | 11 | +39,643 | New | Q1 2026 | May 08, 2026 |
| STATE STREET CORP | History | No change | 33,901 | 300 | 0.0% | 0.0% | 12 | 0 | 0.0% | Q1 2026 | May 15, 2026 |
| CHARLES SCHWAB INVESTMENT MANAGEMENT INC | History | Added to | 31,630 | 280 | 0.0% | 0.0% | 13 | +261 | 0.83% | Q1 2026 | May 15, 2026 |
| Lion Point Capital, LP | History | No change | 31,570 | 280 | 1.67% | 2.43% | 14 | 0 | 0.0% | Q1 2026 | May 15, 2026 |
| MORGAN STANLEY | History | Reduced | 21,700 | 192 | 0.0% | 0.0% | 15 | -3,426 | -13.64% | Q1 2026 | May 15, 2026 |
| GROUP ONE TRADING LLC | History | Added to | 21,124 | 187 | 0.0% | 0.0% | 16 | +1,324 | 6.69% | Q1 2026 | May 13, 2026 |
| TWO SIGMA INVESTMENTS, LP | History | Reduced | 18,794 | 166 | 0.0% | 0.0% | 17 | -6,955 | -27.01% | Q1 2026 | May 15, 2026 |
| NORTHERN TRUST CORP | History | No change | 14,765 | 130 | 0.0% | 0.0% | 18 | 0 | 0.0% | Q1 2026 | May 14, 2026 |
| Invesco Ltd. | History | Added to | 14,547 | 129 | 0.0% | 0.0% | 19 | +187 | 1.3% | Q1 2026 | May 12, 2026 |
| SIMPLEX TRADING, LLC | History | Reduced | 10,270 | 91 | 0.0% | 0.0% | 20 | -662 | -6.06% | Q1 2026 | May 14, 2026 |
| UBS Group AG | History | Added to | 7,030 | 62 | 0.0% | 0.0% | 21 | +2,804 | 66.35% | Q1 2026 | May 05, 2026 |
| BARCLAYS PLC | History | Reduced | 6,507 | 57 | 0.0% | 0.0% | 22 | -925 | -12.45% | Q1 2026 | May 14, 2026 |
| SBI Securities Co., Ltd. | History | No change | 3,482 | 30 | 0.0% | 0.0% | 23 | 0 | 0.0% | Q1 2026 | Apr 27, 2026 |
| Vanguard Global Advisers, LLC | History | New | 1,975 | 17 | 0.0% | — | 24 | +1,975 | New | Q1 2026 | May 08, 2026 |
| FMR LLC | History | Added to | 1,752 | 15 | 0.0% | 0.0% | 25 | +12 | 0.69% | Q1 2026 | May 15, 2026 |
| Rachor Investment Advisory Services, LLC | History | No change | 1,477 | 13 | 0.01% | 0.01% | 26 | 0 | 0.0% | Q1 2026 | May 07, 2026 |
| Tower Research Capital LLC (TRC) | History | New | 794 | 7 | 0.0% | — | 27 | +794 | New | Q1 2026 | May 15, 2026 |
| BNP PARIBAS FINANCIAL MARKETS | History | Reduced | 211 | 1 | 0.0% | 0.0% | 29 | -562 | -72.7% | Q1 2026 | May 12, 2026 |
| ROYAL BANK OF CANADA | History | Added to | 107 | 1 | 0.0% | — | 28 | +98 | 1088.89% | Q1 2026 | May 15, 2026 |
| Physician Wealth Advisors, Inc. | History | No change | 142 | 1 | 0.0% | 0.0% | 30 | 0 | 0.0% | Q1 2026 | Apr 24, 2026 |
| Caption Management, LLC | History | Closed out | 0 | 0 | — | 0.01% | — | -75,000 | -100.0% | Q1 2026 | May 15, 2026 |
| 683 Capital Management, LLC | History | Closed out | 0 | 0 | — | 0.03% | — | -52,314 | -100.0% | Q1 2026 | May 15, 2026 |
| JANE STREET GROUP, LLC | History | Closed out | 0 | 0 | — | 0.0% | — | -29,905 | -100.0% | Q1 2026 | May 12, 2026 |
| Schonfeld Strategic Advisors LLC | History | Closed out | 0 | 0 | — | 0.0% | — | -29,097 | -100.0% | Q1 2026 | May 15, 2026 |
| OMERS ADMINISTRATION Corp | History | Closed out | 0 | 0 | — | 0.0% | — | -14,400 | -100.0% | Q1 2026 | May 15, 2026 |
| GOLDMAN SACHS GROUP INC | History | Closed out | 0 | 0 | — | 0.0% | — | -14,340 | -100.0% | Q1 2026 | May 15, 2026 |
| ExodusPoint Capital Management, LP | History | Closed out | 0 | 0 | — | 0.0% | — | -12,737 | -100.0% | Q1 2026 | May 14, 2026 |
| WELLS FARGO & COMPANY/MN | History | Reduced | 10 | 0 | — | 0.0% | — | -250 | -96.15% | Q1 2026 | May 11, 2026 |
| BANK OF AMERICA CORP /DE/ | History | Closed out | 0 | 0 | — | 0.0% | — | -195 | -100.0% | Q1 2026 | May 15, 2026 |
| Arax Advisory Partners | History | Added to | 6 | 0 | — | — | — | +4 | 200.0% | Q1 2026 | May 13, 2026 |
| Allworth Financial LP | History | No change | 4 | 0 | — | — | — | 0 | 0.0% | Q1 2026 | May 14, 2026 |
| OSAIC HOLDINGS, INC. | History | No change | 8 | 0 | — | — | — | 0 | 0.0% | Q1 2026 | May 15, 2026 |
| Sound Income Strategies, LLC | History | No change | 8 | 0 | — | — | — | 0 | 0.0% | Q1 2026 | Apr 27, 2026 |