SEC Form 4 · Updated Daily
MCRB
— SERES THERAPEUTICS, INC. OwnershipInsider and institutional ownership derived from SEC Form 4 filings. Click any owner to see their holdings across every company they’ve filed on, and how their position has changed over time.
Current Reporting Owners
| Owner | Role | Shares Owned | As Of | Last Activity |
|---|---|---|---|---|
| NESTLE SA | 10%+ Owner | 21,879,753 | 2024-09-30 | — |
| Societe des Produits Nestle S.A. | 10%+ Owner | 21,879,753 | 2024-09-30 | — |
| KANIA EDWIN M JR | 10%+ Owner | 8,022,420 | 2016-05-25 | J |
| Flagship Ventures 2007 General Partner LLC | 10%+ Owner | 8,022,420 | 2016-05-25 | J |
| Flagship Ventures Fund 2007, L.P. | 10%+ Owner | 8,022,420 | 2016-05-25 | J |
| Flagship VentureLabs IV, LLC | 10%+ Owner | 8,022,420 | 2016-05-25 | J |
| NIMCO US, Inc. | 10%+ Owner | 6,888,888 | 2015-07-01 | A |
| Nestle Health Science US Holdings, Inc. | 10%+ Owner | 6,888,888 | 2015-07-01 | A |
| AFEYAN NOUBAR | 10%+ Owner | 5,875,711 | 2022-07-05 | P |
| Flagship Pioneering Inc. | 10%+ Owner | 5,875,711 | 2022-07-05 | P |
| Nutritional Health LTP Fund, L.P. | 10%+ Owner | 5,875,711 | 2022-07-05 | P |
| Nutritional Health LTP Fund General Partner LLC | 10%+ Owner | 5,875,711 | 2022-07-05 | P |
| Flagship Pioneering Fund VII General Partner LLC | 10%+ Owner | 5,825,495 | 2022-07-05 | — |
| Flagship Pioneering Fund VII, L.P. | 10%+ Owner | 5,825,495 | 2022-07-05 | — |
| Flagship Pioneering Fund VI General Partner LLC | 10%+ Owner | 4,434,600 | 2020-11-23 | J |
| Flagship Ventures Fund IV, L.P. | 10%+ Owner | 4,434,600 | 2020-11-23 | J |
| Flagship Ventures Fund IV-Rx, L.P. | 10%+ Owner | 4,434,600 | 2020-11-23 | J |
| Flagship Ventures Fund IV General Partner LLC | 10%+ Owner | 4,434,600 | 2020-11-23 | J |
| Flagship Pioneering Fund VI, L.P. | 10%+ Owner | 4,434,600 | 2020-11-23 | J |
| Pomerantz Roger | Director | 213,976 | 2018-09-07 | S |
| Arkowitz David | Director | 186,381 | 2024-02-15 | M |
| COOK DAVID N | Officer | 147,435 | 2019-01-26 | M |
| Aunins John G. | Officer | 105,250 | 2020-01-26 | M |
| Ege David S. | Officer | 78,703 | 2024-08-15 | M |
| Kender Richard N | Director · Officer | 63,492 | 2022-07-05 | A |
| HUTT PETER BARTON | Director | 50,000 | 2015-06-25 | — |
| Cloghessy Paula | Officer | 48,588 | 2023-10-27 | M |
| Biondi Paul | Director | 47,619 | 2022-07-05 | A |
| von Moltke Lisa | Officer | 44,291 | 2025-02-15 | M |
| Dere Willard H | Director | 31,746 | 2022-07-05 | A |
| Zausner Meryl | Director | 31,746 | 2022-07-05 | A |
| Shaff Eric D. | Director | 12,762 | 2026-08-15 | M |
| Chapman Marcus | Officer | 12,000 | 2019-11-01 | M |
| Brady Kelly | Officer | 8,743 | 2026-08-15 | M |
| Young Teresa L. | Officer | 8,632 | 2026-02-15 | M |
| DesRosier Thomas | Officer | 8,199 | 2026-08-15 | M |
| Henn Matthew R | Officer | 8,076 | 2026-08-15 | M |
| Trucksis Michele | Officer | 7,500 | 2018-01-26 | M |
| Berenson Stephen | Director | 3,589 | 2020-11-23 | J |
| Hashad Wael | Officer | 15 | 2015-12-29 | — |
Recent Filings
| Date | Owner | Activity | Shares | Price | Owned After |
|---|---|---|---|---|---|
| 2026-08-17 | DesRosier Thomas | Open-market sale | 82 | $4.55 | 8,117 |
| 2026-08-17 | Henn Matthew R | Open-market sale | 81 | $4.55 | 7,995 |
| 2026-08-17 | Shaff Eric D. | Open-market sale | 263 | $4.55 | 12,499 |
| 2026-08-17 | Brady Kelly | Open-market sale | 64 | $4.55 | 8,679 |
| 2026-08-15 | DesRosier Thomas | Option exercise (derivative) | 112 | $0.00 | 667 |
| 2026-08-15 | DesRosier Thomas | Option exercise (derivative) | 133 | $0.00 | 265 |
| 2026-08-15 | DesRosier Thomas | Option exercise | 245 | — | 8,199 |
| 2026-08-15 | Henn Matthew R | Option exercise (derivative) | 98 | $0.00 | 585 |
| 2026-08-15 | Henn Matthew R | Option exercise (derivative) | 140 | $0.00 | 282 |
| 2026-08-15 | Henn Matthew R | Option exercise | 238 | — | 8,076 |
| 2026-08-15 | Shaff Eric D. | Option exercise (derivative) | 332 | $0.00 | 1,993 |
| 2026-08-15 | Shaff Eric D. | Option exercise (derivative) | 390 | $0.00 | 783 |
| 2026-08-15 | Shaff Eric D. | Option exercise | 722 | — | 12,762 |
| 2026-08-15 | Brady Kelly | Option exercise (derivative) | 91 | $0.00 | 548 |
| 2026-08-15 | Brady Kelly | Option exercise (derivative) | 90 | $0.00 | 179 |
| 2026-08-15 | Brady Kelly | Option exercise | 181 | — | 8,743 |
| 2026-07-08 | DesRosier Thomas | Grant / award (derivative) | 7,500 | $0.00 | 7,500 |
| 2026-07-08 | Brady Kelly | Grant / award (derivative) | 18,750 | $0.00 | 18,750 |
| 2026-07-08 | Berenson Stephen | Grant / award (derivative) | 6,500 | $0.00 | 6,500 |
| 2026-07-08 | Rosiello Robert L. | Grant / award (derivative) | 6,500 | $0.00 | 6,500 |
| 2026-07-08 | Shaff Eric D. | Grant / award (derivative) | 6,500 | $0.00 | 6,500 |
| 2026-07-08 | Ausiello Dennis A | Grant / award (derivative) | 6,500 | $0.00 | 6,500 |
| 2026-07-08 | Dere Willard H | Grant / award (derivative) | 6,500 | $0.00 | 6,500 |
| 2026-07-08 | Fraser Claire | Grant / award (derivative) | 6,500 | $0.00 | 6,500 |
| 2026-07-08 | Thorell Marella | Grant / award (derivative) | 7,500 | $0.00 | 7,500 |
| 2026-07-08 | Henn Matthew R | Grant / award (derivative) | 25,000 | $0.00 | 25,000 |
| 2026-07-08 | Kender Richard N | Grant / award (derivative) | 50,000 | $0.00 | 50,000 |
| 2026-07-08 | Graves Kurt | Grant / award (derivative) | 6,500 | $0.00 | 6,500 |
| 2026-07-01 | Ausiello Dennis A | Grant / award (derivative) | 7,508 | $0.00 | 7,508 |
| 2026-07-01 | Rosiello Robert L. | Grant / award (derivative) | 7,508 | $0.00 | 7,508 |
| 2026-07-01 | Berenson Stephen | Grant / award (derivative) | 7,508 | $0.00 | 7,508 |
| 2026-05-18 | Henn Matthew R | Open-market sale | 77 | $7.53 | 7,838 |
| 2026-05-18 | Brady Kelly | Open-market sale | 59 | $7.53 | 8,562 |
| 2026-05-18 | DesRosier Thomas | Open-market sale | 79 | $7.53 | 7,954 |
| 2026-05-18 | Shaff Eric D. | Open-market sale | 259 | $7.53 | 12,040 |
| 2026-05-15 | Henn Matthew R | Option exercise (derivative) | 97 | $0.00 | 683 |
| 2026-05-15 | Henn Matthew R | Option exercise (derivative) | 141 | $0.00 | 422 |
| 2026-05-15 | Henn Matthew R | Option exercise | 238 | — | 7,915 |
| 2026-05-15 | Brady Kelly | Option exercise (derivative) | 91 | $0.00 | 639 |
| 2026-05-15 | Brady Kelly | Option exercise (derivative) | 89 | $0.00 | 269 |
Source: SEC EDGAR Form 4 filings. For informational purposes only — not investment advice.