Updated Jul 16, 2026 · Last SEC filing 2026-07-10
Seres Therapeutics, Inc. (MCRB) has filed 19 SEC Form 4 insider transactions in the last 90 days, with the most recent on 2026-07-10. 5 Form 8-K material event filings were reported by MCRB in the last 90 days. 1 Form 144 notices of proposed sale were filed for MCRB stock. InsiderAlpha tracks every MCRB SEC filing — Form 4, Form 144, and 8-K — in real time, including Rule 10b5-1 plan detection.
| SEC CIK | 0001609809 |
|---|
| Form 4 filings (90d) | 19 |
|---|---|
| Form 8-K filings (90d) | 5 |
| Form 144 notices (90d) | 1 |
| Latest Form 4 filing | 2026-07-10 |
| Date | Insider | Role | Transaction | Shares | Price | Value | Filing |
|---|---|---|---|---|---|---|---|
| DesRosier Thomas | See Remarks | S — Open-market sale | 79 | $7.53 | $595 | SEC | |
| Shaff Eric D. | Insider | S — Open-market sale | 259 | $7.53 | $2K | SEC | |
| Brady Kelly | See Remarks | S — Open-market sale | 59 | $7.53 | $444 | SEC | |
| Henn Matthew R | See Remarks | S — Open-market sale | 77 | $7.53 | $580 | SEC | |
| Shaff Eric D. | Insider | M — Option exercise | 722 | — | — | SEC | |
| Brady Kelly | See Remarks | M — Option exercise | 180 | — | — | SEC | |
| DesRosier Thomas | See Remarks | M — Option exercise | 244 | — | — | SEC | |
| Henn Matthew R | See Remarks | M — Option exercise | 238 | — | — | SEC | |
| Henn Matthew R | See Remarks | S — Open-market sale [10b5-1] | 89 | $8.47 | $754 | SEC | |
| DesRosier Thomas | See Remarks | M — Option exercise [10b5-1] | 244 | — | — | SEC | |
| Young Teresa L. | See Remarks | S — Open-market sale [10b5-1] | 75 | $8.47 | $635 | SEC | |
| DesRosier Thomas | See Remarks | S — Open-market sale [10b5-1] | 78 | $8.47 | $661 | SEC | |
| Shaff Eric D. | Insider | S — Open-market sale [10b5-1] | 259 | $8.47 | $2K | SEC | |
| Shaff Eric D. | Insider | M — Option exercise [10b5-1] | 723 | — | — | SEC | |
| Young Teresa L. | See Remarks | M — Option exercise [10b5-1] | 231 | — | — | SEC |
All transactions sourced from SEC EDGAR Form 4 filings for Seres Therapeutics, Inc. (MCRB). Updated in real time as new filings are submitted to the SEC.
| Insider | Form 4 filings | Total transaction value |
|---|---|---|
| Shaff Eric D. | 5 | $2K |
| Brady Kelly | 5 | $444 |
| Henn Matthew R | 5 | $580 |
| DesRosier Thomas | 5 | $595 |
| Ausiello Dennis A | 2 | — |
Form 144 must be filed before insiders sell restricted or control stock above SEC thresholds. A cluster of Form 144 notices often precedes a wave of insider distribution.
SEC Form 4 transactions are reported with a one-letter code indicating the type of transaction. Common codes you'll see in MCRB insider filings:
| P | Open-market purchase by the insider |
|---|---|
| S | Open-market sale by the insider |
| A | Grant, award, or other acquisition from the issuer |
| M | Exercise or conversion of derivative security (e.g. options) |
| F | Payment of exercise price or tax liability via share withholding |
| G | Bona-fide gift of securities |
| D | Disposition to the issuer (e.g. share buyback participation) |
| J | Other acquisition or disposition |
| X | Exercise of in-the-money or at-the-money derivative security |
| C | Conversion of derivative security |
| V | Transaction voluntarily reported earlier than required |
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