<SEC-DOCUMENT>0000950170-24-016712.txt : 20240216
<SEC-HEADER>0000950170-24-016712.hdr.sgml : 20240216
<ACCEPTANCE-DATETIME>20240216214816
ACCESSION NUMBER:		0000950170-24-016712
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20240214
FILED AS OF DATE:		20240216
DATE AS OF CHANGE:		20240216

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			DesRosier Thomas
		CENTRAL INDEX KEY:			0001435744
		ORGANIZATION NAME:           	

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-37465
		FILM NUMBER:		24650418

	MAIL ADDRESS:	
		STREET 1:		65 HAYDEN AVENUE
		CITY:			LEXINGTON
		STATE:			MA
		ZIP:			02421

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			Seres Therapeutics, Inc.
		CENTRAL INDEX KEY:			0001609809
		STANDARD INDUSTRIAL CLASSIFICATION:	PHARMACEUTICAL PREPARATIONS [2834]
		ORGANIZATION NAME:           	03 Life Sciences
		IRS NUMBER:				274326290
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		200 SIDNEY STREET
		CITY:			CAMBRIDGE
		STATE:			MA
		ZIP:			02139
		BUSINESS PHONE:		617 945 9626

	MAIL ADDRESS:	
		STREET 1:		200 SIDNEY STREET
		CITY:			CAMBRIDGE
		STATE:			MA
		ZIP:			02139

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	Seres Health, Inc.
		DATE OF NAME CHANGE:	20140603
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
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    <periodOfReport>2024-02-14</periodOfReport>

    <issuer>
        <issuerCik>0001609809</issuerCik>
        <issuerName>Seres Therapeutics, Inc.</issuerName>
        <issuerTradingSymbol>MCRB</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001435744</rptOwnerCik>
            <rptOwnerName>DesRosier Thomas</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O SERES THERAPEUTICS, INC.</rptOwnerStreet1>
            <rptOwnerStreet2>101 CAMBRIDGE PARK DRIVE</rptOwnerStreet2>
            <rptOwnerCity>CAMBRIDGE</rptOwnerCity>
            <rptOwnerState>MA</rptOwnerState>
            <rptOwnerZipCode>02140</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>false</isDirector>
            <isOfficer>true</isOfficer>
            <isTenPercentOwner>false</isTenPercentOwner>
            <isOther>false</isOther>
            <officerTitle>Chief Legal Officer and EVP</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <aff10b5One>true</aff10b5One>

    <nonDerivativeTable>
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                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2024-02-15</value>
            </transactionDate>
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                <transactionCode>M</transactionCode>
                <equitySwapInvolved>false</equitySwapInvolved>
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            <transactionAmounts>
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                <transactionPricePerShare>
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                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>124516</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
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                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
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                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Stock Option (Right to Buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>1.10</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2024-02-14</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>false</equitySwapInvolved>
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            <transactionAmounts>
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                </transactionShares>
                <transactionPricePerShare>
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                <transactionAcquiredDisposedCode>
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            </transactionAmounts>
            <exerciseDate>
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            </exerciseDate>
            <expirationDate>
                <value>2034-02-13</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>213750</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
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                    <value>287905</value>
                </transactionShares>
                <transactionPricePerShare>
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                <transactionAcquiredDisposedCode>
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            <exerciseDate>
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            <expirationDate>
                <value>2034-02-13</value>
            </expirationDate>
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                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>287905</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
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                    <value>287905</value>
                </sharesOwnedFollowingTransaction>
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                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
        <derivativeTransaction>
            <securityTitle>
                <value>Restricted Stock Units</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <footnoteId id="F1"/>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2024-02-14</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>false</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>35625</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
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                </transactionAcquiredDisposedCode>
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                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>35625</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
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                <sharesOwnedFollowingTransaction>
                    <value>35625</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
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                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
        <derivativeTransaction>
            <securityTitle>
                <value>Restricted Stock Units</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <footnoteId id="F1"/>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2024-02-15</value>
            </transactionDate>
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                <transactionFormType>4</transactionFormType>
                <transactionCode>M</transactionCode>
                <equitySwapInvolved>false</equitySwapInvolved>
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                <transactionShares>
                    <value>10625</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
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            <exerciseDate>
                <footnoteId id="F7"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F7"/>
            </expirationDate>
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                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>10625</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>31875</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Each restricted stock unit represents a contingent right to receive one share of Issuer common stock.</footnote>
        <footnote id="F2">The sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 instruction adopted by the reporting person on March 2, 2023, solely with the intent to cover taxes in connection with the vesting of the restricted stock units.</footnote>
        <footnote id="F3">The price reported in column 4 is a weighted average of the price.  These shares were sold in multiple transactions at prices ranging from $1.08 to $1.115, inclusive.  The reporting person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.</footnote>
        <footnote id="F4">The option will vest as to 25% of the shares on February 14, 2025. The remainder of the shares will vest in 12 equal quarterly installments thereafter.</footnote>
        <footnote id="F5">The option will vest, if at all, in two substantially equal installments upon achievement of a 30-day trailing average public market closing price per share of the Issuer's common stock greater than or equal to $3.00 and $5.00, respectively.</footnote>
        <footnote id="F6">The restricted stock units will vest and settle as to 25% of the restricted stock units on February 15, 2025. The remainder of the restricted stock units will vest and settle in 12 equal quarterly installments thereafter. The restricted stock units have no expiration date.</footnote>
        <footnote id="F7">The restricted stock units have vested and settled as to 25% of the restricted stock units on February 15, 2024. The remainder of the restricted stock units will vest and settle in 12 equal quarterly installments thereafter. The restricted stock units have no expiration date.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Thomas J. DesRosier</signatureName>
        <signatureDate>2024-02-16</signatureDate>
    </ownerSignature>
</ownershipDocument>
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</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
