Seres Therapeutics (MCRB)
Develops oral bacterial consortia for infection, immune, and inflammatory conditions.
$5.54
Pre-market+0.03 (+0.54%)
At close$5.51(+6.37%)
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Breakdown13F · 13D/G · Form 4
| Institutions36 holders · as of Mar 31, 2026 | 23.82% | 2.31M shares | |
| Insiders6 holders · as of Aug 18, 2026 | 0.49% | 47.8K shares | |
| Strategic holders1 holder · as of Oct 2, 2024 | 11.30% | 1.09M shares | |
| Otherremainder | 64.39% | 6.24M shares |
9.68M company shares as of Aug 21, 2026 · institutions as of Mar 31, 2026 · holders as of their latest filing
The share count has not been confirmed by a second filing; stakes use it as it stands.
Institutions13F, as of Mar 31, 2026
36 holders · 2.31M shares · 6 new positions · 16 increased · 8 reduced · 9 closed
| Holder | Shares | % outstanding | Chg q/q | Filed |
|---|---|---|---|---|
| Flagship Pioneering Inc. | 1.16M | 11.94% | 0 | May 15, 2026 |
| Vanguard Capital Management LLC | 294.1K | 3.04% | +294.1Knew | May 15, 2026 |
| Marshall Wace, LLP | 139.5K | 1.44% | +19.4K | May 15, 2026 |
| Vontobel Holding Ltd. | 138.5K | 1.43% | +35.2K | May 8, 2026 |
| Susquehanna International Group, LLP | 105.3K | 1.09% | −74.6K | May 15, 2026 |
| BlackRock, Inc. | 102.0K | 1.05% | −1.6K | May 13, 2026 |
| Geode Capital Management, LLC | 74.8K | 0.77% | −11.3K | May 15, 2026 |
| American Century Companies Inc | 62.3K | 0.64% | +46.0K | May 15, 2026 |
Ownership statements13D/G · 5% or more, as filed
| Holder | % of class | Shares | Form | Filed |
|---|---|---|---|---|
| FMR LLC | 12.80% | 13G | Feb 12, 2025 ↗ |
Insider tradesForm 4
Latest trades
| Date | Insider | Type | Shares | Avg price | Owned after |
|---|---|---|---|---|---|
| Aug 17, 2026 | Kelly Bradyofficer: See Remarks | Sale | 64 | $4.55 | 8,679 |
| Aug 17, 2026 | Eric D. Shaffdirector | Sale | 263 | $4.55 | 12,499 |
| Aug 17, 2026 | Thomas DesRosierofficer: See Remarks | Sale | 82 | $4.55 | 8,117 |
| Aug 17, 2026 | Matthew R. Hennofficer: See Remarks | Sale | 81 | $4.55 | 7,995 |
| May 18, 2026 | Matthew R. Hennofficer: See Remarks | Sale | 77 | $7.53 | 7,838 |
| May 18, 2026 | Kelly Bradyofficer: See Remarks | Sale | 59 | $7.53 | 8,562 |
| May 18, 2026 | Thomas DesRosierofficer: See Remarks | Sale | 79 | $7.53 | 7,954 |
| May 18, 2026 | Eric D. Shaffdirector | Sale | 259 | $7.53 | 12,040 |
| Feb 15, 2026 | Matthew R. Hennofficer: See Remarks | Sale | 89 | $8.47 | 7,677 |
| Feb 15, 2026 | Thomas DesRosierofficer: See Remarks | Sale | 78 | $8.47 | 7,789 |
CongressHouse and Senate disclosures
Not reported.