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

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2013-05-15</periodOfReport>

    <notSubjectToSection16>1</notSubjectToSection16>

    <issuer>
        <issuerCik>0001465740</issuerCik>
        <issuerName>Two Harbors Investment Corp.</issuerName>
        <issuerTradingSymbol>TWO</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001288136</rptOwnerCik>
            <rptOwnerName>Pine River Capital Management L.P.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>601 CARLSON PARKWAY</rptOwnerStreet1>
            <rptOwnerStreet2>SUITE 330</rptOwnerStreet2>
            <rptOwnerCity>MINNETONKA</rptOwnerCity>
            <rptOwnerState>MN</rptOwnerState>
            <rptOwnerZipCode>55305</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>1</isOther>
            <otherText>Group</otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001387809</rptOwnerCik>
            <rptOwnerName>TAYLOR BRIAN</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O PINE RIVER CAPITAL MANAGEMENT</rptOwnerStreet1>
            <rptOwnerStreet2>601 CARLSON PARKWAY, SUITE 330</rptOwnerStreet2>
            <rptOwnerCity>MINNETONKA</rptOwnerCity>
            <rptOwnerState>MN</rptOwnerState>
            <rptOwnerZipCode>55305</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>1</isOther>
            <otherText>Group</otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001475577</rptOwnerCik>
            <rptOwnerName>Pine River Capital Management LLC</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>601 CARLSON PARKWAY, SUITE 330</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>MINNETONKA</rptOwnerCity>
            <rptOwnerState>MN</rptOwnerState>
            <rptOwnerZipCode>55305</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>1</isOther>
            <otherText>Group</otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001387810</rptOwnerCik>
            <rptOwnerName>Pine River MASTER FUND LTD.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O PINE RIVER CAPITAL MANAGEMENT L.P.</rptOwnerStreet1>
            <rptOwnerStreet2>601 CARLSON PARKWAY, SUITE 330</rptOwnerStreet2>
            <rptOwnerCity>MINNETONKA</rptOwnerCity>
            <rptOwnerState>MN</rptOwnerState>
            <rptOwnerZipCode>55305</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>1</isOther>
            <otherText>Group</otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001439357</rptOwnerCik>
            <rptOwnerName>Nisswa Acquisition Master Fund Ltd.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O MAPLES CORPORATE SVCS LIMITED</rptOwnerStreet1>
            <rptOwnerStreet2>PO BOX 309, UGLAND HOUSE</rptOwnerStreet2>
            <rptOwnerCity>GRAND CAYMAN</rptOwnerCity>
            <rptOwnerState>E9</rptOwnerState>
            <rptOwnerZipCode>KY1-1104</rptOwnerZipCode>
            <rptOwnerStateDescription>CAYMAN ISLANDS</rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>1</isOther>
            <otherText>Group</otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Warrants</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>10.25</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2013-05-15</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>500000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>2.2318</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <value>2009-10-28</value>
            </exerciseDate>
            <expirationDate>
                <value>2013-11-07</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>500000</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>0</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See Footnote (1)</value>
                    <footnoteId id="F1"/>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">The securities are owned directly by Pine River Master Fund Ltd. and Nisswa Acquisition Master Fund Ltd. (the &quot;Funds&quot;), for which Pine River Capital Management L.P. (the &quot;Partnership&quot;) is the Investment Manager.  Mr. Taylor is the sole member of Pine River Capital Management LLC (the &quot;LLC&quot;), an entity which is the general partner of the Partnership.  Each of Mr. Taylor, the Partnership and the LLC disclaim beneficial ownership of any of the securities owned by the Funds other than to the extent of his or its pecuniary interest therein, and this report shall not be deemed an admission that Mr. Taylor, the Partnership or the LLC is the beneficial owner of such securities for purposes of Section 16 of the Securities Exchange Act of 1934, as amended, or otherwise.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Brian Taylor, Sole member, on behalf of Pine River Capital Management LLC</signatureName>
        <signatureDate>2013-05-17</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>/s/ Brian Taylor, Chief Executive Officer, on behalf of Pine River Capital Management L.P.</signatureName>
        <signatureDate>2013-05-17</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>/s/ Brian Taylor, Director, on behalf of Pine River Master Fund Ltd.</signatureName>
        <signatureDate>2013-05-17</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>/s/ Brian Taylor, Director, on behalf of Nisswa Acquisition Master Fund Ltd.</signatureName>
        <signatureDate>2013-05-17</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>/s/ Brian Taylor</signatureName>
        <signatureDate>2013-05-17</signatureDate>
    </ownerSignature>
</ownershipDocument>
