Welcome to our dedicated page for Seres Therapeutics SEC filings (Ticker: MCRB), a comprehensive resource for investors and traders seeking official regulatory documents including 10-K annual reports, 10-Q quarterly earnings, 8-K material events, and insider trading forms.
Seres Therapeutics, Inc. filings document the disclosure record of a Nasdaq-listed biotechnology company focused on live biotherapeutic and microbiome-based therapeutic programs. Its Form 8-K reports furnish quarterly and annual financial results, operational updates, Regulation FD corporate presentations, and material-event disclosures involving pipeline priorities, clinical and regulatory matters, capital allocation, cost-reduction actions, and financing or partnership activity.
The company’s proxy materials cover annual meeting mechanics, stockholder voting, board governance, executive compensation, and equity-award information. SEC filings also identify Seres’ common stock registered under the Exchange Act and traded on the Nasdaq Global Select Market under the symbol MCRB.
Seres Therapeutics, Inc. officer Thomas DesRosier reported routine equity compensation activity and a small share sale. On February 15, 2026, he acquired common stock through the exercise and settlement of restricted stock units, then sold 78 shares of common stock at $8.47 per share. The sale was executed under a pre-arranged Rule 10b5-1 instruction adopted on March 2, 2023, solely to cover taxes tied to the restricted stock unit vesting. After these transactions, he continued to hold common stock and restricted stock units directly.
Seres Therapeutics, Inc. officer Matthew R. Henn reported RSU vesting and related share movements. On February 15, 2026, he acquired 141 and 98 shares of common stock through the exercise and settlement of restricted stock units, plus another 239 shares, and then sold 89 common shares at $8.47 per share. The sale was made under a pre-arranged Rule 10b5-1 instruction adopted on April 13, 2023, solely to cover taxes triggered by the RSU vesting. Following these transactions, he directly held 7,677 common shares.
Seres Therapeutics (MCRB) reported insider equity activity for an executive officer. EVP, Chief Commercial & Strategy Officer Teresa L. Young exercised restricted stock units (RSUs) into common stock on November 15, 2025, receiving 3,998, 132, and 98 shares in three separate transactions. On the same date, she sold 1,042 shares of common stock at a price of $17.30 per share, and held 8,401 shares directly after the reported transactions. The filing notes the sales were made under a pre-arranged Rule 10b5-1 trading instruction adopted on March 5, 2023, with the stated purpose of covering taxes related to RSU vesting.
Seres Therapeutics, Inc. director reports RSU vesting and small share sale. On 11/15/2025, the reporting person exercised restricted stock units that converted into 390 and 331 shares of common stock, increasing direct holdings and reflecting ongoing equity compensation. On the same date, 217 shares of common stock were sold at $17.30 per share under a pre-arranged Rule 10b5-1 trading instruction intended solely to cover taxes tied to the RSU vesting. After these transactions, the director directly beneficially owned 11,113 shares of common stock, along with 1,954 and 2,989 restricted stock units that vest in scheduled quarterly installments.
Seres Therapeutics, Inc. (MCRB) reported insider equity activity by its Chief Legal Officer, EVP, Co-Chief Executive Officer, and Co-President on 11/15/2025. The filing shows the exercise and settlement of restricted stock units into 132 shares and 112 shares of common stock, each RSU granting one share upon vesting. On the same date, 76 shares of common stock were sold at $17.30 per share under a Rule 10b5-1 trading instruction adopted on March 2, 2023, solely to cover taxes tied to RSU vesting. After these transactions, the reporting person directly owned 7,623 shares of common stock and retained 664 and 1,001 restricted stock units, which vest in scheduled quarterly installments and have no expiration date.
Seres Therapeutics (MCRB) reported insider activity by its Chief Scientific Officer and EVP, Matthew R. Henn. On November 15, 2025, several blocks of restricted stock units (RSUs) were converted into common stock, including 3,998, 140, and 98 shares. After these transactions and a sale, Henn held 7,527 shares of common stock directly.
The filing shows a sale of 1,257 shares of common stock at $17.30 per share. According to the explanation, these sales were made under a pre-arranged Rule 10b5-1 instruction adopted on April 13, 2023, and were executed solely to cover taxes arising from RSU vesting. The RSUs vest over time in scheduled installments, with certain awards having no expiration date and vesting quarterly after initial 25% vesting dates.
Seres Therapeutics (MCRB) reported Q3 2025 results. The company posted net income from continuing operations of $8.2 million for the quarter, driven by a $27.2 million gain on sale related to the VOWST business and $2.8 million of other income that included TSA reimbursements, against $22.8 million of operating expenses. Grant revenue was $351 thousand in Q3 2025, reflecting a CARB-X award tied to SER-155 development.
For the nine months ended September 30, 2025, net income from continuing operations was $21.0 million, including a year‑to‑date $79.6 million gain on the VOWST sale. Cash and cash equivalents were $47.6 million as of September 30, 2025, and total stockholders’ equity rose to $43.7 million from $13.8 million at year‑end 2024. The company disclosed substantial doubt about its ability to continue as a going concern based on current cash resources and forecasted operations.
Seres is advancing SER‑155, supported by a CARB‑X grant of up to $3.6 million, and recorded $1.0 million of restructuring costs tied to a ~25% workforce reduction announced on September 23, 2025. Shares outstanding were 8,764,664 as of September 30, 2025, and 9,046,519 as of October 31, 2025.
Seres Therapeutics (MCRB) furnished an update via Form 8-K announcing financial results for the quarter ended September 30, 2025 and providing operational updates. The company also shared an updated corporate presentation for investors.
The press release is furnished as Exhibit 99.1 and the investor slide deck as Exhibit 99.2. Consistent with Items 2.02 and 7.01, these materials are furnished, not filed, and are not subject to Section 18 liabilities or incorporation by reference except as expressly stated.
Seres Therapeutics, Inc. is cutting its workforce by approximately 25%, including reductions that took effect in August 2025, as part of a plan to reduce operating costs and extend its available cash. The company expects to incur cash charges of about $1.0 to $1.4 million in the fourth quarter of 2025, primarily for severance.
Based on these cost-saving measures and current operating plans, Seres expects its cash runway to extend into the second quarter of 2026. The company cautions that these expectations rely on current assumptions and are subject to significant risks, including its need for additional funding, its ability to continue as a going concern, its history of losses, and the possibility that the cost savings initiative does not deliver the anticipated benefits.
Matthew R. Henn, Chief Scientific Officer and EVP of Seres Therapeutics (MCRB), was granted 3,998 restricted stock units (RSUs) on 09/26/2025. Each RSU converts to one share of common stock and the award was reported as acquired at a $0 price. The RSUs are scheduled to vest in a single installment on 11/15/2025, subject to satisfaction of the award agreement terms, and the RSUs have no expiration date. Following the reported transaction the filing shows beneficial ownership of 3,998 shares reported as direct.