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

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2019-02-14</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001045425</issuerCik>
        <issuerName>RAIT Financial Trust</issuerName>
        <issuerTradingSymbol>RASFN</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0000904853</rptOwnerCik>
            <rptOwnerName>Amster Howard</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>23811 CHAGRIN BLVD # 200</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>BEACHWOOD</rptOwnerCity>
            <rptOwnerState>OH</rptOwnerState>
            <rptOwnerZipCode>44122-5525</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>RASFN RAIT FINANCIAL TRUST 8.875% SERIES C CUMULATIVE</value>
            </securityTitle>
            <transactionDate>
                <value>2019-02-14</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>30000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>3</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>1134514</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>SEE EXPLANATION BELOW</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <remarks>Howard Amster Maintains Direct Ownership of the Following Shares;
RASFP RAIT Financial Trust 7.75% Series A Cumulative 272,590
RASFO RAIT Financial Trust 8.375% Series B Cumulative 132,380
RASFN RAIT Financial Trust 8.875% Series C Cumulative 60,598
Howard Amster Maintains Indirect Ownership of the Following Shares;
RASFP RAIT Financial Trust 7.75% Series A Cumulative
Amster L.P. Gen Prtr 18,400
Laughlin Holdings LLC Pres. Maj. Mbr 42,400
NewAx Inc. Maj. Shrhldr 1,100
Pleasant Lake Apts L.P. Prs. Gen Ptnr 86,928
Ramat Securities Ltd LLC Maj Mbr 65,700
Somerset Outlet Centers L.P Pres Gen Ptnr 39,300
RASFO RAIT Financial Trust 8.375% Series B Cumulative
Amster L.P. Gen Ptnr 33,677
Horizon Group Properties Inc. Maj. Shrdr 2,400
Pleasant Lake Apts Corp Sole Shrdr 3,400
Pleasant Lake Apts L.P. Pres Gen Ptnr 152,799
Pleasant Lake Skoien Inv LLC Pres Maj Mbr 4,974
Ramat Securities Ltd LLC Maj Mbr 43,959
RASFN RAIT Financial Trust 8.875% Series C Cumulative
Amster L.P. Gen Ptnr 1,300
Laughlin Holding LLC Pres Maj Mmbr 15,031
Pleasant Lake Apts L.P. Pres Gen Ptnr 120,773
Pleasant Lake Skoien Inv LLC Pres Maj Mbr 6,300
Ramat Securities Ltd LLC Maj Mbr 14,405
Somerset Outlet Centers L.P. Pres Gen Prtr 16,100</remarks>

    <ownerSignature>
        <signatureName>HOWARD AMSTER</signatureName>
        <signatureDate>2019-02-15</signatureDate>
    </ownerSignature>
</ownershipDocument>
