MCRB Form 4: Executive Receives 3,998 RSUs at $0 Price

Rhea-AI Filing Summary

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.

Insights

Financial Analyst

TL;DR: A routine, non-cash equity award to an executive that modestly increases direct share exposure and aligns incentives.

The Form 4 documents a grant of 3,998 RSUs to the reporting person, recorded as acquired at $0 and vesting on 11/15/2025. This is a standard compensation mechanism for senior executives and is typically intended for retention and alignment with shareholder interests. The size of the award (3,998 shares) appears modest relative to most public company equity grants and does not by itself indicate a material change to capitalization or control. No sale, exercise, or cash consideration is reported.

Corporate Governance Expert

TL;DR: Disclosure is complete for the grant; timing and single-installment vesting are typical but should be reviewed against the executive's award agreement.

The filing clearly states the grant date, number of RSUs, vesting date, absence of expiration, and beneficial ownership post-grant. The report is signed by an attorney-in-fact and identifies the reporting person as an officer (CSO and EVP). From a governance perspective, this appears to be standard compensation disclosure under Section 16 with no indications of accelerated vesting, transfer, or derivative instruments. Investors may review the award agreement for performance conditions, which are not described in the Form 4.

SEC Form 4

FORM 4

UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940

OMB APPROVAL

OMB Number:			3235-0287
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Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

1. Name and Address of Reporting Person^*

Henn Matthew R

(Last) (First) (Middle)

C/O SERES THERAPEUTICS, INC.

101 CAMBRIDGE PARK DRIVE

(Street)

CAMBRIDGE MA 02140

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
Seres Therapeutics, Inc. [ MCRB ]

5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

	Director		10% Owner
X	Officer (give title below)		Other (specify below)
	See Remarks

3. Date of Earliest Transaction (Month/Day/Year)
09/26/2025

4. If Amendment, Date of Original Filed (Month/Day/Year)

6. Individual or Joint/Group Filing (Check Applicable Line)

X	Form filed by One Reporting Person
	Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	3. Transaction Code (Instr. 8)		4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
			Code	V	Amount	(A) or (D)	Price

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	4. Transaction Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares
Restricted Stock Units	(1)	09/26/2025		A		3,998		(2)	(2)	Common Stock	3,998	$0	3,998	D

Explanation of Responses:

1. Each restricted stock unit ("RSU") represents a contingent right to receive one share of Issuer common stock.

2. The RSUs will vest in a single installment on November 15, 2025, subject to the Reporting Person's satisfaction of the terms contemplated in the award agreement.The RSUs have no expiration date.

Remarks:

Chief Scientific Officer and EVP

	/s/ Thomas J. DesRosier, attorney-in-fact for Matthew R. Henn	09/30/2025
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.

FAQ

What did Matthew R. Henn report on Form 4 for MCRB?

He reported a grant of 3,998 restricted stock units (RSUs) acquired on 09/26/2025, each converting to one share of common stock.

When do the RSUs granted to Matthew R. Henn vest?

The RSUs vest in a single installment on 11/15/2025, subject to the terms of the award agreement.

What price was reported for the RSU grant on the Form 4?

The RSUs were reported with a price of $0 on the acquisition line of the Form 4.

How many shares does the Form 4 show Matthew R. Henn beneficially owns after the grant?

The filing shows 3,998 shares beneficially owned following the reported transaction, recorded as direct ownership.

What is Matthew R. Henn's role at Seres Therapeutics as noted in the filing?

He is identified as Chief Scientific Officer and Executive Vice President (EVP).