<SEC-DOCUMENT>0001179110-20-004078.txt : 20200323
<SEC-HEADER>0001179110-20-004078.hdr.sgml : 20200323
<ACCEPTANCE-DATETIME>20200323173744
ACCESSION NUMBER:		0001179110-20-004078
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20200319
FILED AS OF DATE:		20200323
DATE AS OF CHANGE:		20200323

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			STAFFORD JOHN S III
		CENTRAL INDEX KEY:			0001218981

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-36182
		FILM NUMBER:		20735919

	MAIL ADDRESS:	
		STREET 1:		230 SOUTH LASALLE STREET 400
		CITY:			CHICAGO
		STATE:			IL
		ZIP:			60604

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Ronin Capital, LLC
		CENTRAL INDEX KEY:			0001512282
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-36182
		FILM NUMBER:		20735920

	BUSINESS ADDRESS:	
		STREET 1:		350 N. ORLEANS, SUITE 2N
		CITY:			CHICAGO
		STATE:			IL
		ZIP:			60654
		BUSINESS PHONE:		312-244-5284

	MAIL ADDRESS:	
		STREET 1:		350 N. ORLEANS, SUITE 2N
		CITY:			CHICAGO
		STATE:			IL
		ZIP:			60654

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			Xencor Inc
		CENTRAL INDEX KEY:			0001326732
		STANDARD INDUSTRIAL CLASSIFICATION:	PHARMACEUTICAL PREPARATIONS [2834]
		IRS NUMBER:				201622502
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		111 WEST LEMON AVE
		CITY:			MONROVIA
		STATE:			CA
		ZIP:			91016
		BUSINESS PHONE:		626-305-5900

	MAIL ADDRESS:	
		STREET 1:		111 WEST LEMON AVE
		CITY:			MONROVIA
		STATE:			CA
		ZIP:			91016
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>edgar.xml
<DESCRIPTION>FORM 4 -
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2020-03-19</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001326732</issuerCik>
        <issuerName>Xencor Inc</issuerName>
        <issuerTradingSymbol>XNCR</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001512282</rptOwnerCik>
            <rptOwnerName>Ronin Capital, LLC</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>350 N. ORLEANS STREET</rptOwnerStreet1>
            <rptOwnerStreet2>SUITE 2N</rptOwnerStreet2>
            <rptOwnerCity>CHICAGO</rptOwnerCity>
            <rptOwnerState>IL</rptOwnerState>
            <rptOwnerZipCode>60654-1975</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001218981</rptOwnerCik>
            <rptOwnerName>STAFFORD JOHN S III</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>350 N. ORLEANS STREET</rptOwnerStreet1>
            <rptOwnerStreet2>SUITE 2N</rptOwnerStreet2>
            <rptOwnerCity>CHICAGO</rptOwnerCity>
            <rptOwnerState>IL</rptOwnerState>
            <rptOwnerZipCode>60654-1975</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2020-03-19</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>26800</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>28.2311</value>
                    <footnoteId id="F1"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>5063200</value>
                    <footnoteId id="F3"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2020-03-20</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>50770</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>29.8925</value>
                    <footnoteId id="F2"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>5012430</value>
                    <footnoteId id="F3"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">This transaction was executed in multiple trades at prices ranging from $27.37 to $28.86. The price reported above reflects the weighted average purchase price. The reporting person hereby undertakes to provide upon request to the SEC staff, the issuer or a security holder of the issuer full information regarding the number of shares and prices at which the transactions were effected.</footnote>
        <footnote id="F2">This transaction was executed in multiple trades at prices ranging from $28.09 to $31.65. The price reported above reflects the weighted average purchase price. The reporting person hereby undertakes to provide upon request to the SEC staff, the issuer or a security holder of the issuer full information regarding the number of shares and prices at which the transactions were effected.</footnote>
        <footnote id="F3">The reported shares of common stock of Xencor, Inc. are held in a Class C Capital Account of John S. Stafford, III at Ronin Capital, LLC (&quot;Ronin&quot;), a limited liability company owned and managed by Mr. Stafford. Mr. Stafford is the indirect beneficial owner of all of the shares of common stock of Xencor, Inc. held of record by Ronin.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Agnes Burda, authorized signatory</signatureName>
        <signatureDate>2020-03-23</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>/s/ John S. Stafford, III</signatureName>
        <signatureDate>2020-03-23</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
