Every Form 4 that Seres Therapeutics Inc (MCRB) has filed with the SEC in the last 12 months is listed below, newest first, and each one links through to the document itself with the summary and the scores our analysis gives it.
A Form 4 covers the transactions officers, directors and large holders report, so if you follow MCRB and want that one kind of document rather than the whole filing history, this is the page to keep. The company's other filings, of every form, are on the full MCRB filings page.
Seres Therapeutics, Inc. (MCRB) executive Brady Kelly, EVP and Chief Operating Officer, reported equity transactions involving company stock. On August 15, 2026, a total of 181 shares of Common Stock were acquired upon the vesting and settlement of 181 Restricted Stock Units, each RSU representing one share of common stock. On August 17, 2026, Kelly then sold 64 shares of Common Stock at $4.55 per share. According to the disclosure, the sale was effected under a Rule 10b5-1 trading plan adopted on November 26, 2025, with the stated intent to cover taxes related to the RSU vesting.
Seres Therapeutics, Inc. (MCRB) director Eric D. Shaff reported equity award activity and a small share sale. On August 15, 2026, restricted stock units covering 722 shares of common stock vested and settled into common shares. On August 17, 2026, he sold 263 common shares at $4.55 per share pursuant to a pre-arranged Rule 10b5-1 trading instruction solely to cover taxes related to the RSU vesting.
For Seres Therapeutics, Inc. (MCRB), President and Chief Scientific Officer Matthew R. Henn reported equity compensation activity and a small share sale. On August 15, 2026, he exercised and settled 238 restricted stock units into an equal number of common shares, stemming from RSU grants with vesting schedules described in the footnotes. On August 17, 2026, he then sold 81 common shares at $4.55 per share in an open-market transaction executed under a Rule 10b5-1 trading plan adopted on April 13, 2023, solely to cover taxes related to the RSU vesting.
Seres Therapeutics, Inc. (MCRB) reported insider equity activity by EVP and Chief Legal Officer Thomas DesRosier. On August 15, 2026, a total of 245 shares of common stock were acquired upon settlement of restricted stock units, with two RSU awards of 133 and 112 units each converting into common shares, where each unit represents one share and has no expiration date. On August 17, 2026, 82 shares of common stock were sold at $4.55 per share in an open-market transaction made under a Rule 10b5-1 trading plan adopted on March 2, 2023, described as intended solely to cover taxes related to the RSU vesting.
Seres Therapeutics, Inc. director Kurt Graves received a grant of stock options to acquire 6,500 shares of common stock at an exercise price of $7.14 per share. The options expire on July 7, 2036 and vest on the earlier of July 8, 2027 or the day immediately prior to the first annual meeting of stockholders occurring after July 8, 2026.
Seres Therapeutics, Inc. reported that director and officer Richard N. Kender received a grant of stock options covering 50,000 shares of common stock at an exercise price of $9.13 per share. These options vest in 36 equal monthly installments beginning on March 2, 2026, and are scheduled to expire on March 3, 2036. Following this grant, Kender holds stock options for 50,000 shares directly.
Seres Therapeutics, Inc. reported that officer Matthew R. Henn received a grant of stock options for 25,000 shares of common stock. The options carry an exercise price of $9.13 per share and expire on March 3, 2036. According to the vesting terms, 25% of the options vest on March 2, 2027, with the remaining shares vesting in 12 equal quarterly installments thereafter, contingent on continued service.
Seres Therapeutics, Inc. reported that company officer Marella Thorell received a compensatory grant of stock options covering 7,500 shares of common stock at an exercise price of $9.13 per share. The options were awarded at no cost and will vest as to 25% of the shares on March 2, 2027, with the remaining shares vesting in 12 equal quarterly installments thereafter, subject to continued service.
Seres Therapeutics, Inc. reported that director Claire Fraser received a grant of stock options covering 6,500 shares of common stock at an exercise price of $7.14 per share. The options expire on July 7, 2036 and vest and become exercisable on the earlier of July 8, 2027 or the day immediately prior to the first annual meeting of stockholders occurring after July 8, 2026. Following this award, Fraser holds options for 6,500 shares directly.
Seres Therapeutics, Inc. director Willard H. Dere received a grant of stock options covering 6,500 shares of common stock at an exercise price of $7.14 per share. The options vest and become exercisable on the earlier of July 8, 2027 or the day immediately prior to the first annual meeting of stockholders occurring after July 8, 2026, and expire on July 7, 2036. Following this award, Dere holds options for 6,500 shares directly.
Seres Therapeutics, Inc. director Dennis A. Ausiello received a grant of stock options covering 6,500 shares of common stock at an exercise price of $7.14 per share. The options vest and become exercisable on the earlier of July 8, 2027 or the day immediately prior to the first annual stockholder meeting occurring after July 8, 2026, and expire on July 7, 2036. Following this grant, he holds 6,500 derivative securities directly.
Seres Therapeutics, Inc. director Eric D. Shaff received a grant of stock options covering 6,500 shares of common stock. The options have an exercise price of $7.14 per share and expire on July 7, 2036. Vesting occurs on the earlier of July 8, 2027 or the day immediately prior to the first annual meeting of stockholders occurring after July 8, 2026.
Seres Therapeutics, Inc. reported that director Robert L. Rosiello received a grant of stock options covering 6,500 shares of common stock at an exercise price of $7.14 per share. These options vest and become exercisable on the earlier of July 8, 2027 or the day immediately before the first annual stockholder meeting occurring after July 8, 2026, and expire on July 7, 2036. Following this grant, Rosiello holds 6,500 derivative securities directly.
Seres Therapeutics, Inc. director Stephen Berenson received a grant of stock options covering 6,500 shares of common stock at an exercise price of $7.14 per share. These options vest and become exercisable on the earlier of July 8, 2027 or the day immediately prior to the first annual meeting of stockholders occurring after July 8, 2026, and expire on July 7, 2036. Following this grant, he holds 6,500 derivative securities directly.
Seres Therapeutics, Inc. reported that officer Brady Kelly received a grant of stock options covering 18,750 shares of common stock at an exercise price of $9.13 per share. The options expire on March 3, 2036, with 25% vesting on March 2, 2027 and the remaining 75% vesting in 12 equal quarterly installments thereafter.
Seres Therapeutics, Inc. reported that officer Thomas DesRosier received a grant of stock options covering 7,500 shares of common stock at an exercise price of $9.13 per share. The options expire on March 3, 2036. According to the vesting schedule, 25% of the shares vest on March 2, 2027, with the remaining shares vesting in 12 equal quarterly installments thereafter.
Seres Therapeutics director Stephen Berenson received a new stock option grant covering 7,508 shares of common stock. The option has an exercise price of $7.94 per share and was awarded as a compensation-related grant, not an open-market purchase or sale.
The option vests in four equal quarterly installments on October 1, 2026, January 1, 2027, April 1, 2027, and July 1, 2027, with the final vesting date moving to the day before the 2027 annual stockholder meeting if that meeting occurs before July 1, 2027. Vesting is conditioned on Berenson continuing to serve as a non-employee director through each vesting date.
Seres Therapeutics director grants stock options
Seres Therapeutics, Inc. director Robert L. Rosiello received a grant of stock options covering 7,508 shares of common stock at an exercise price of $7.94 per share. These options were awarded as compensation rather than purchased on the open market.
The options vest in four equal quarterly installments on October 1, 2026, January 1, 2027, April 1, 2027, and July 1, 2027, with the final installment vesting earlier if the 2027 annual stockholder meeting occurs before July 1, 2027, subject to his continued service on the board as a non-employee director.
Seres Therapeutics director Dennis A. Ausiello received a grant of stock options covering 7,508 shares of common stock. The options have an exercise price of $7.94 per share and expire on July 1, 2036. The award vests in four equal quarterly installments on October 1, 2026, January 1, 2027, April 1, 2027, and July 1, 2027, with the final installment vesting earlier if the 2027 annual stockholder meeting occurs before July 1, 2027. Vesting requires his continued service on the board as a non-employee director through each vesting date.
Seres Therapeutics director Eric D. Shaff reported routine stock transactions tied to vesting of restricted stock units. On May 18, 2026, he sold 259 shares of common stock at $7.53 per share in an open-market sale executed under a pre-arranged Rule 10b5-1 instruction adopted to cover taxes from RSU vesting.
On May 15, 2026, Shaff exercised derivative awards to acquire 722 shares of common stock at a conversion price of $0.00 as RSUs vested and settled. Following these transactions, he directly holds 12,040 shares of common stock, and additional RSUs remain outstanding that continue to vest in quarterly installments.
Seres Therapeutics, Inc. officer Thomas DesRosier reported a small set of equity transactions. He sold 79 shares of common stock at $7.53 per share in an open-market sale executed under a pre-arranged Rule 10b5-1 plan intended to cover taxes from restricted stock unit (RSU) vesting.
On the same date, RSUs covering 244 shares were converted into common stock at a $0.00 exercise price, and additional RSUs for 111 and 133 shares converted into common stock. After these transactions, he directly holds 7,954 common shares plus remaining RSU awards that continue to vest over time.
Seres Therapeutics, Inc. officer Matthew R. Henn reported several equity transactions. On May 15, 2026, he exercised restricted stock units (RSUs) that converted into 238 shares of common stock at a conversion price of $0.00 per share. The RSUs each represent a contingent right to one share of common stock and vest in quarterly installments. On May 18, 2026, he completed an open-market sale of 77 common shares at $7.53 per share, executed under a pre-arranged Rule 10b5-1 instruction adopted to cover taxes related to RSU vesting. Following these transactions, he directly held 7,838 common shares and 422 RSUs as reported in the filing, indicating a relatively small sale compared with his remaining equity position.
Seres Therapeutics officer Brady Kelly reported routine equity compensation activity and a small tax-related sale. On May 15, 2026, Kelly exercised restricted stock units, converting 180 shares in total into common stock at a stated price of $0.00 per share. The filing explains that each restricted stock unit is a right to receive one share of Seres common stock and describes quarterly vesting schedules for grants that began vesting on February 15, 2024 and February 15, 2025. On May 18, 2026, Kelly sold 59 shares of common stock at $7.53 per share, specifically to cover taxes tied to the RSU vesting. Following these transactions, Kelly directly holds 8,562 shares of common stock, indicating that the sale was small relative to the overall position.
Seres Therapeutics, Inc. reported that officer Kelly Brady received a grant of stock options for 56,250 shares of common stock on March 4, 2026. The options have an exercise price of $9.13 per share and are held as a direct derivative position.
The option grant vests over time: 25% of the shares vest on March 2, 2027, with the remaining shares vesting in 12 equal quarterly installments after that date. This is a compensation-related award rather than an open-market stock purchase or sale.
Kender Richard N reported acquisition or exercise transactions in this Form 4 filing.
Seres Therapeutics, Inc. director and officer Richard N. Kender reported receiving a grant of stock options covering 150,000 shares of common stock. These options give him the right to buy company shares and were reported as a direct beneficial holding.
According to the filing, the option award vests and becomes exercisable in 36 equal monthly installments, providing long-term, incremental equity-based compensation tied to his continued service with the company.
Seres Therapeutics, Inc. disclosed that officer Matthew R. Henn received a grant of stock options covering 75,000 shares of common stock on March 4, 2026. These options give him the right to buy company shares if they vest and are exercised in the future.
According to the vesting schedule, 25% of the option shares will vest on March 2, 2027, with the remaining shares vesting in 12 equal quarterly installments thereafter. This filing reflects an equity-based compensation award rather than an open-market share purchase or sale.
Seres Therapeutics, Inc. reported that officer Marella Thorell received a grant of stock options covering 22,500 shares of the company’s stock. This is classified as a grant or award acquisition, not a market purchase or sale.
According to the vesting terms, 25% of the option shares will vest on March 2, 2027, with the remaining shares vesting in 12 equal quarterly installments after that date. Following this grant, Thorell’s directly held option position from this award totals 22,500 option shares.
DesRosier Thomas reported acquisition or exercise transactions in this Form 4 filing.
Seres Therapeutics, Inc. reported that officer Thomas DesRosier received a grant of stock options covering 22,500 shares of the company’s stock. No cash was paid for this award, which is described as a “Stock Option (right to buy).”
According to the vesting terms, 25% of the option shares will vest on March 2, 2027. The remaining shares will then vest in 12 equal quarterly installments after that date, tying the award to continued service over several years.
Seres Therapeutics director Eric D. Shaff reported several equity transactions on February 15, 2026 tied to his restricted stock units (RSUs). He exercised RSU-derived rights for a total of 723 shares of common stock, then sold 259 shares of common stock at $8.47 per share under a pre-arranged Rule 10b5-1 instruction, which the filing states was intended solely to cover taxes from RSU vesting. Following these moves, he directly held 11,577 shares of common stock, while his RSU awards continue to vest in scheduled quarterly installments.
Seres Therapeutics officer Teresa L. Young reported multiple Form 4 transactions involving restricted stock units and common stock. She acquired 231 shares of common stock on February 15, 2026 through exercises of restricted stock units at $0.00 per share, then sold 75 common shares at $8.47 per share. The sale was executed under a pre-arranged Rule 10b5-1 instruction adopted on March 5, 2023 to cover taxes related to vesting of restricted stock units.
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.
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.