MCRB · Insider Trading
Seres Therapeutics, Inc.
Every open-market purchase and sale reported by MCRB officers, directors and 10%+ beneficial owners on SEC Form 4, which must be filed within two business days of the transaction. Sales often reflect scheduled 10b5-1 plans or tax withholding rather than a directional view, so read counts alongside the size and the filer.
| Filed | Insider | Role | Type | Shares | Value |
|---|---|---|---|---|---|
| 2026-08-18 | Eric D. Shaff | Director | MIXED | +459 | −$1.20K |
| 2026-08-18 | Matthew R Henn | See Remarks | MIXED | +157 | −$369 |
| 2026-08-18 | Kelly Brady | See Remarks | MIXED | +117 | −$291 |
| 2026-08-18 | Thomas DesRosier | See Remarks | MIXED | +163 | −$373 |
| 2026-07-10 | Eric D. Shaff | Director | A | +6,500 deriv. | — |
| 2026-07-10 | Thomas DesRosier | See Remarks | A | +7,500 deriv. | — |
| 2026-07-10 | Matthew R Henn | See Remarks | A | +25,000 deriv. | — |
| 2026-07-10 | Richard N Kender | See Remarks | A | +50,000 deriv. | — |
| 2026-07-10 | Stephen Berenson | Director | A | +6,500 deriv. | — |
| 2026-07-10 | Robert L. Rosiello | Director | A | +6,500 deriv. | — |
| 2026-07-10 | Kurt Graves | Director | A | +6,500 deriv. | — |
| 2026-07-10 | Willard H Dere | Director | A | +6,500 deriv. | — |
| 2026-07-10 | Marella Thorell | See Remarks | A | +7,500 deriv. | — |
| 2026-07-10 | Claire Fraser | Director | A | +6,500 deriv. | — |
| 2026-07-10 | Dennis A Ausiello | Director | A | +6,500 deriv. | — |
| 2026-07-10 | Kelly Brady | See Remarks | A | +18,750 deriv. | — |
| 2026-07-02 | Robert L. Rosiello | Director | A | +7,508 deriv. | — |
| 2026-07-02 | Dennis A Ausiello | Director | A | +7,508 deriv. | — |
| 2026-07-02 | Stephen Berenson | Director | A | +7,508 deriv. | — |
| 2026-05-19 | Eric D. Shaff | Director | MIXED | +463 | −$1.95K |
| 2026-05-19 | Thomas DesRosier | See Remarks | MIXED | +165 | −$595 |
| 2026-05-19 | Matthew R Henn | See Remarks | MIXED | +161 | −$580 |
| 2026-05-19 | Kelly Brady | See Remarks | MIXED | +121 | −$444 |
| 2026-03-11 | Kelly Brady | See Remarks | A | +56,250 deriv. | — |
| 2026-03-06 | Thomas DesRosier | See Remarks | A | +22,500 deriv. | — |
| 2026-03-06 | Matthew R Henn | See Remarks | A | +75,000 deriv. | — |
| 2026-03-06 | Richard N Kender | See Remarks | A | +150,000 deriv. | — |
| 2026-03-06 | Marella Thorell | See Remarks | A | +22,500 deriv. | — |
| 2026-02-18 | Eric D. Shaff | Director | MIXED | +464 | −$2.19K |
| 2026-02-18 | Teresa L. Young | See Remarks | MIXED | +156 | −$635 |
| 2026-02-18 | Matthew R Henn | See Remarks | MIXED | +150 | −$754 |
| 2026-02-18 | Thomas DesRosier | See Remarks | MIXED | +166 | −$661 |
| 2025-11-18 | Thomas DesRosier | See Remarks | MIXED | +168 | −$1.31K |
| 2025-11-18 | Teresa L. Young | See Remarks | MIXED | +3,186 | −$18.03K |
| 2025-11-18 | Matthew R Henn | See Remarks | MIXED | +2,979 | −$21.75K |
| 2025-11-18 | Eric D. Shaff | Director | MIXED | +504 | −$3.75K |
| 2025-09-30 | Teresa L. Young | See Remarks | A | +3,998 deriv. | — |
| 2025-09-30 | Matthew R Henn | See Remarks | A | +3,998 deriv. | — |
| 2025-08-19 | Matthew R Henn | See Remarks | MIXED | +165 | −$1.22K |
| 2025-08-19 | Thomas DesRosier | See Remarks | MIXED | +168 | −$1.27K |
| 2025-08-19 | Eric D. Shaff | Director | MIXED | +507 | −$3.61K |
| 2025-08-19 | Teresa L. Young | See Remarks | MIXED | +171 | −$982 |
| 2025-08-06 | Robert L. Rosiello | Director | A | +10,000 deriv. | — |
| 2025-07-02 | Dennis A Ausiello | Director | A | +6,452 deriv. | — |
| 2025-07-02 | Stephen Berenson | Director | A | +11,470 deriv. | — |
| 2025-07-02 | Claire Fraser | Director | A | +6,452 deriv. | — |
| 2025-05-19 | Teresa L. Young | See Remarks | MIXED | +168 | −$459 |
| 2025-05-19 | Thomas DesRosier | Chief Legal Officer and EVP | MIXED | +165 | −$575 |
| 2025-05-19 | Eric D. Shaff | CEO and President | MIXED | +501 | −$1.60K |
| 2025-05-19 | Matthew R Henn | See Remarks | MIXED | +161 | −$561 |
| Insider | Role | Shares Held | Value |
|---|---|---|---|
| Eric D. Shaff | Director | 12,762 | $25.27K |
| Kelly Brady | See Remarks | 8,679 | $17.18K |
| Teresa L. Young | See Remarks | 8,632 | $17.09K |
| Thomas DesRosier | See Remarks | 8,117 | $16.07K |
| Matthew R Henn | See Remarks | 8,076 | $15.99K |
| Richard N Kender | See Remarks | 3,175 | $6.29K |
| Paul Biondi | Director | 2,381 | $4.71K |
| Lisa von Moltke | See Remarks | 2,215 | $4.39K |
| Willard H Dere | Director | 1,587 | $3.14K |
| Stephen Berenson | Director | 179 | $354 |
Form 4 reports a change in beneficial ownership by an officer, director or 10%+ holder, and must be filed within two business days of the transaction — so this is close to real time, unlike the 45-day-lagged 13F institutional data.
Transaction codes matter more than the raw buy/sell count. Code P is an open-market purchase — an insider choosing to buy with their own money, which is the signal most research treats as informative. Code S is a sale, but sales are frequently pre-scheduled under a 10b5-1 plan or cover tax withholding on vesting equity, so a run of sales often says nothing directional. Codes A and M are grants and option exercises rather than open-market decisions.
Full filing history and per-insider positions are on the MCRB quote page; the site-wide leaderboard is on the insider transactions hub.
Market data may be delayed, incomplete, or inaccurate. Not a recommendation to buy, sell, or hold any security. Verify quotes with your broker before trading. See Terms §17.