Seres Therapeutics, Inc. (MCRB) Insider Trading
Over the last 3 months, MCRB insiders made 0 open-market buys and 4 sales, a net sale of -$2K (SEC Form 4). Over the last 6 months, 10 institutions increased and 9 reduced their position (13F).
Insider Activity
Sentiment
0/100
Buys (3m)
0
Sells (3m)
4
Net (3m)
-$2.2K
Insider trades by month Buys Sells
May
Aug
Nov
Feb
May
Aug
Context3-month price -31.8%Institutions reducing (13F)
| Date | Insider | Type | Shares | Price |
|---|---|---|---|---|
| Aug 18, 2026 | Henn Matthew Rofficer: See Remarks | Sell | 81 | $4.55 |
| Aug 18, 2026 | DesRosier Thomasofficer: See Remarks | Sell | 82 | $4.55 |
| Aug 18, 2026 | Shaff Eric D.director | Option | 332 | — |
| Aug 18, 2026 | Brady Kellyofficer: See Remarks | Option | 90 | — |
| Aug 18, 2026 | Henn Matthew Rofficer: See Remarks | Option | 238 | — |
| Aug 18, 2026 | DesRosier Thomasofficer: See Remarks | Option | 112 | — |
| Aug 18, 2026 | Shaff Eric D.director | Sell | 263 | $4.55 |
| Aug 18, 2026 | Brady Kellyofficer: See Remarks | Option | 91 | — |
| Aug 18, 2026 | Brady Kellyofficer: See Remarks | Sell | 64 | $4.55 |
| Aug 18, 2026 | Henn Matthew Rofficer: See Remarks | Option | 98 | — |
| Aug 18, 2026 | DesRosier Thomasofficer: See Remarks | Option | 133 | — |
| Aug 18, 2026 | Brady Kellyofficer: See Remarks | Option | 181 | — |
| Aug 18, 2026 | Shaff Eric D.director | Option | 722 | — |
| Aug 18, 2026 | Henn Matthew Rofficer: See Remarks | Option | 140 | — |
| Aug 18, 2026 | Shaff Eric D.director | Option | 390 | — |
| Aug 18, 2026 | DesRosier Thomasofficer: See Remarks | Option | 245 | — |
| Jul 10, 2026 | Henn Matthew Rofficer: See Remarks | Grant | 25,000 | $9.13 |
| Jul 10, 2026 | Kender Richard Ndirector, officer: See Remarks | Grant | 50,000 | $9.13 |
| Jul 10, 2026 | Brady Kellyofficer: See Remarks | Grant | 18,750 | $9.13 |
| Jul 10, 2026 | Dere Willard Hdirector | Grant | 6,500 | $7.14 |
| Jul 10, 2026 | Graves Kurtdirector | Grant | 6,500 | $7.14 |
| Jul 10, 2026 | Rosiello Robert L.director | Grant | 6,500 | $7.14 |
| Jul 10, 2026 | Thorell Marellaofficer: See Remarks | Grant | 7,500 | $9.13 |
| Jul 10, 2026 | DesRosier Thomasofficer: See Remarks | Grant | 7,500 | $9.13 |
| Jul 10, 2026 | Fraser Clairedirector | Grant | 6,500 | $7.14 |
| Jul 10, 2026 | Berenson Stephendirector | Grant | 6,500 | $7.14 |
| Jul 10, 2026 | Ausiello Dennis Adirector | Grant | 6,500 | $7.14 |
| Jul 10, 2026 | Shaff Eric D.director | Grant | 6,500 | $7.14 |
| Jul 2, 2026 | Ausiello Dennis Adirector | Grant | 7,508 | $7.94 |
| Jul 2, 2026 | Rosiello Robert L.director | Grant | 7,508 | $7.94 |
Source: MCRB SEC Form 4 filings, latest Aug 18, 2026. For informational purposes only — not investment advice.
Institutional activity (13F)
How institutions changed their MCRB positions over the last 6 months (SEC Form 13F).
Increased
10
New positions
6
Reduced
9
Sold out
35
Largest moves
| Institution | Action | Shares | Filed |
|---|---|---|---|
| FLAGSHIP PIONEERING INC. | Unchanged | 1.2M | May 15, 2026 |
| VANGUARD CAPITAL MANAGEMENT LLC | New Position | 294K | May 15, 2026 |
| SUSQUEHANNA INTERNATIONAL GROUP, LLP | Reduced | 227K | May 15, 2026 |
| MARSHALL WACE, LLP | Increased | 140K | May 15, 2026 |
| VONTOBEL HOLDING LTD. | Increased | 138K | May 8, 2026 |
| BLACKROCK, INC. | Reduced | 102K | May 13, 2026 |
| GEODE CAPITAL MANAGEMENT, LLC | Reduced | 75K | May 15, 2026 |
| AMERICAN CENTURY COMPANIES INC | Increased | 62K | May 15, 2026 |
| CITADEL ADVISORS LLC | Reduced | 60K | May 15, 2026 |
| VANGUARD FIDUCIARY TRUST CO | New Position | 40K | May 8, 2026 |
| STATE STREET CORP | Unchanged | 34K | May 15, 2026 |
| CHARLES SCHWAB INVESTMENT MANAGEMENT INC | Increased | 32K | May 15, 2026 |
| LION POINT CAPITAL, LP | Unchanged | 32K | May 15, 2026 |
| MORGAN STANLEY | Reduced | 22K | May 15, 2026 |
| TWO SIGMA INVESTMENTS, LP | Reduced | 19K | May 15, 2026 |
Source: SEC Form 13F filings. For informational purposes only — not investment advice.