<SEC-DOCUMENT>0001729851-21-000003.txt : 20210811
<SEC-HEADER>0001729851-21-000003.hdr.sgml : 20210811
<ACCEPTANCE-DATETIME>20210811163848
ACCESSION NUMBER:		0001729851-21-000003
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20210806
FILED AS OF DATE:		20210811
DATE AS OF CHANGE:		20210811

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Cooper Steve D
		CENTRAL INDEX KEY:			0001729851

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-38371
		FILM NUMBER:		211164032

	MAIL ADDRESS:	
		STREET 1:		2235 ENTERPRISE ST STE 110
		CITY:			ESCONDIDO
		STATE:			CA
		ZIP:			92029

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			ONE STOP SYSTEMS, INC.
		CENTRAL INDEX KEY:			0001394056
		STANDARD INDUSTRIAL CLASSIFICATION:	ELECTRONIC COMPUTERS [3571]
		IRS NUMBER:				330885351
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		2235 ENTERPRISE ST STE 110
		CITY:			ESCONDIDO
		STATE:			CA
		ZIP:			92029
		BUSINESS PHONE:		760-745-9883

	MAIL ADDRESS:	
		STREET 1:		2235 ENTERPRISE ST STE 110
		CITY:			ESCONDIDO
		STATE:			CA
		ZIP:			92029

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	ONE STOP SYSTEMS INC
		DATE OF NAME CHANGE:	20070322
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>primary_doc.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2021-08-06</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001394056</issuerCik>
        <issuerName>ONE STOP SYSTEMS, INC.</issuerName>
        <issuerTradingSymbol>OSS</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001729851</rptOwnerCik>
            <rptOwnerName>Cooper Steve D</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>1340 DEXTER PL</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>ESCONDIDO</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>92029</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>One Stop Systems, Inc</value>
            </securityTitle>
            <transactionDate>
                <value>2021-08-06</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>473</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>6.05</value>
                    <footnoteId id="F1"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>3042202</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>Shares owned directly by Cooper Revocable Trust dated April 25, 2001, a ten percent owner</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>One Stop Systems, Inc</value>
            </securityTitle>
            <transactionDate>
                <value>2021-08-09</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>49527</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>6.21</value>
                    <footnoteId id="F1"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>2992675</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>Shares owned directly by Cooper Revocable Trust dated April 25, 2001, a ten percent owner</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>One Stop Systems, Inc</value>
            </securityTitle>
            <transactionDate>
                <value>2021-08-10</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>4420</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>6.25</value>
                    <footnoteId id="F1"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>2988255</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>Shares owned directly by Cooper Revocable Trust dated April 25, 2001, a ten percent owner</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">Prices are weighted average of trades made that day.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>Steve Cooper</signatureName>
        <signatureDate>2021-08-10</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>Steve Cooper, Trustee, Cooper Revocable Trust dated April 25, 2001</signatureName>
        <signatureDate>2021-08-10</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
