<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0508</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2023-12-15</periodOfReport>

    <issuer>
        <issuerCik>0001409493</issuerCik>
        <issuerName>CHIMERA INVESTMENT CORP</issuerName>
        <issuerTradingSymbol>CIM</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001869475</rptOwnerCik>
            <rptOwnerName>Kortman Kelley</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O:  CHIMERA INVESTMENT CORPORATION</rptOwnerStreet1>
            <rptOwnerStreet2>630 FIFTH AVENUE, SUITE 2400</rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10111</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isOfficer>true</isOfficer>
            <officerTitle>Principal Accounting Officer</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <aff10b5One>false</aff10b5One>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2023-12-15</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>F</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>2030</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>5.02</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>39859</value>
                    <footnoteId id="F2"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Series B Preferred Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>5800</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">Shares reported were withheld for payment of taxes associated with the vesting of prior grants of RSUs.</footnote>
        <footnote id="F2">Includes shares of the common stock of Chimera Investment Corporation (&quot;Chimera common stock&quot;) underlying restricted stock units (&quot;RSUs&quot;).  Each RSU has the economic equivalent of one share of Chimera common stock. The RSUs are scheduled to vest one-third per year on the first, second and third anniversaries of the grant date and shall be settled 100% in shares of Chimera common stock.  The reporting person does not intend to report the vesting of the RSUs nor the delivery of the shares of common stock. Dividend equivalent rights (&quot;DERs&quot;) issued on RSUs are included in the reporting person's common stock holding balance.  Each DER is the economic equivalent of one share of Chimera common stock.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Kelley Kortman</signatureName>
        <signatureDate>2023-12-19</signatureDate>
    </ownerSignature>
</ownershipDocument>
