Seres Therapeutics's three largest insider shareholders as of September 09, 2026 are Health Ltp Fund General Partner Llc Nutritional (TenPercentOwner, 11.70Mn shares), Health Ltp Fund General Partner Llc Nutritional (TenPercentOwner, 585.06K shares), Health Ltp Fund General Partner Llc Nutritional (TenPercentOwner, 585.06K shares).
| # | Insider | Position | Direct | Indirect | Total | Share of Insiders | Last Filed |
|---|---|---|---|---|---|---|---|
| 1 | Health Ltp Fund General Partner Llc Nutritional | TenPercentOwner | 0 | 11,701,206 | 11,701,206 | 98.6% | 07 Jul, 2022 |
| 2 | Moltke Lisa Von | Officer | 39,875 | 0 | 39,875 | 0.3% | 19 Feb, 2025 |
| 3 | Meryl Zausner | Director | 31,746 | 0 | 31,746 | 0.3% | 06 Jul, 2022 |
| 4 | David Arkowitz | Chief Financial Officer | 20,727 | 0 | 20,727 | 0.2% | 16 Feb, 2024 |
| 5 | Eric D. Shaff | Ceo And President | 17,316 | 0 | 17,316 | 0.1% | 18 Aug, 2026 |
| 6 | Thomas Desrosier | Chief Legal Officer And Evp | 13,344 | 0 | 13,344 | 0.1% | 18 Aug, 2026 |
| 7 | Matthew R Henn | Officer | 10,376 | 0 | 10,376 | 0.1% | 18 Aug, 2026 |
| 8 | Kelly Brady | Officer | 8,679 | 0 | 8,679 | 0.1% | 18 Aug, 2026 |
| 9 | Teresa L. Young | Officer | 8,557 | 0 | 8,557 | 0.1% | 18 Feb, 2026 |
| 10 | David S. Ege | Officer | 8,451 | 0 | 8,451 | 0.1% | 19 Aug, 2024 |
| 11 | Paula Cloghessy | Officer | 3,872 | 0 | 3,872 | 0.0% | 31 Oct, 2023 |
| 12 | Richard N Kender | Director | 3,175 | 0 | 3,175 | 0.0% | 06 Jul, 2022 |
| 13 | Paul Biondi | Director | 2,381 | 0 | 2,381 | 0.0% | 06 Jul, 2022 |
| 14 | Willard H Dere | Director | 1,587 | 0 | 1,587 | 0.0% | 06 Jul, 2022 |
Each row is that insider’s most recently reported position, from Form 4 filings over the last 60 months — which is why this total does not tie to the quarterly series above, where a quarter counts only the insiders who filed in it. Shares held through a fund or institutional portfolio are counted on the institutional ownership page instead.
| Date | Insider | Position | Transaction | Shares | Price | Value | Shares Held After | Ownership |
|---|---|---|---|---|---|---|---|---|
| 15 Aug, 2026 | Thomas Desrosier | Officer | Acquired M | 245 | — | — | 8,199 | Direct |
| 15 Aug, 2026 | Matthew R Henn | Officer | Acquired M | 238 | — | — | 8,076 | Direct |
| 15 Aug, 2026 | Eric D. Shaff | Director | Acquired M | 722 | — | — | 12,762 | Direct |
| 15 Aug, 2026 | Kelly Brady | Officer | Acquired M | 181 | — | — | 8,743 | Direct |
| 17 Aug, 2026 | Eric D. Shaff | Director | Disposed S | 263 | $4.55 | $1.20K | 12,499 | Direct |
| 17 Aug, 2026 | Thomas Desrosier | Officer | Disposed S | 82 | $4.55 | $373 | 8,117 | Direct |
| 17 Aug, 2026 | Kelly Brady | Officer | Disposed S | 64 | $4.55 | $291 | 8,679 | Direct |
| 17 Aug, 2026 | Matthew R Henn | Officer | Disposed S | 81 | $4.55 | $369 | 7,995 | Direct |
| 15 Aug, 2026 | Matthew R Henn | Officer | Disposed M | 140 | $0.00 | $0 | 282 | Direct |
| 15 Aug, 2026 | Thomas Desrosier | Officer | Disposed M | 133 | $0.00 | $0 | 265 | Direct |
| 15 Aug, 2026 | Eric D. Shaff | Director | Disposed M | 390 | $0.00 | $0 | 783 | Direct |
| 15 Aug, 2026 | Kelly Brady | Officer | Disposed M | 90 | $0.00 | $0 | 179 | Direct |
| 15 Aug, 2026 | Kelly Brady | Officer | Disposed M | 91 | $0.00 | $0 | 548 | Direct |
| 15 Aug, 2026 | Eric D. Shaff | Director | Disposed M | 332 | $0.00 | $0 | 1,993 | Direct |
| 15 Aug, 2026 | Matthew R Henn | Officer | Disposed M | 98 | $0.00 | $0 | 585 | Direct |
| 15 Aug, 2026 | Thomas Desrosier | Officer | Disposed M | 112 | $0.00 | $0 | 667 | Direct |
| 08 Jul, 2026 | Matthew R Henn | Officer | Acquired A | 25,000 | $0.00 | $0 | 25,000 | Direct |
| 08 Jul, 2026 | Richard N Kender | Director, Officer | Acquired A | 50,000 | $0.00 | $0 | 50,000 | Direct |
| 08 Jul, 2026 | Claire Fraser | Director | Acquired A | 6,500 | $0.00 | $0 | 6,500 | Direct |
| 08 Jul, 2026 | Willard H Dere | Director | Acquired A | 6,500 | $0.00 | $0 | 6,500 | Direct |