<SEC-DOCUMENT>0001580808-20-000087.txt : 20200805
<SEC-HEADER>0001580808-20-000087.hdr.sgml : 20200805
<ACCEPTANCE-DATETIME>20200805161248
ACCESSION NUMBER:		0001580808-20-000087
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20200803
FILED AS OF DATE:		20200805
DATE AS OF CHANGE:		20200805

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Singer Eric
		CENTRAL INDEX KEY:			0001443284

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-36343
		FILM NUMBER:		201077409

	MAIL ADDRESS:	
		STREET 1:		825 THIRD AVENUE
		STREET 2:		33RD FLOOR
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10022

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			VIEX Opportunities Fund, LP Series One
		CENTRAL INDEX KEY:			0001606750
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-36343
		FILM NUMBER:		201077410

	BUSINESS ADDRESS:	
		STREET 1:		C/O VIEX CAPITAL ADVISORS, LLC
		STREET 2:		825 THIRD AVENUE, 33RD FLOOR
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10022
		BUSINESS PHONE:		212-752-5750

	MAIL ADDRESS:	
		STREET 1:		C/O VIEX CAPITAL ADVISORS, LLC
		STREET 2:		825 THIRD AVENUE, 33RD FLOOR
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10022

	FORMER NAME:	
		FORMER CONFORMED NAME:	VIEX Opportunities Fund, LP
		DATE OF NAME CHANGE:	20151228

	FORMER NAME:	
		FORMER CONFORMED NAME:	Vertex Opportunities Fund, LP
		DATE OF NAME CHANGE:	20140429

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			VIEX Opportunities Fund, LP - Series Two
		CENTRAL INDEX KEY:			0001659404
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-36343
		FILM NUMBER:		201077411

	BUSINESS ADDRESS:	
		STREET 1:		C/O VIEX CAPITAL ADVISORS, LLC
		STREET 2:		825 THIRD AVENUE, 33RD FLOOR
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10022
		BUSINESS PHONE:		212-752-5750

	MAIL ADDRESS:	
		STREET 1:		C/O VIEX CAPITAL ADVISORS, LLC
		STREET 2:		825 THIRD AVENUE, 33RD FLOOR
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10022

	FORMER NAME:	
		FORMER CONFORMED NAME:	VIEX Opportunities Fund, LP Series Two
		DATE OF NAME CHANGE:	20151228

	FORMER NAME:	
		FORMER CONFORMED NAME:	Vertex Opportunities Fund, LP Series Two
		DATE OF NAME CHANGE:	20151125

	FORMER NAME:	
		FORMER CONFORMED NAME:	Vertex Opportuniteis Fund, LP Series Two
		DATE OF NAME CHANGE:	20151125

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			VIEX Special Opportunities Fund II, LP
		CENTRAL INDEX KEY:			0001619127
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-36343
		FILM NUMBER:		201077412

	BUSINESS ADDRESS:	
		STREET 1:		C/O VIEX CAPITAL ADVISORS, LLC
		STREET 2:		825 THIRD AVENUE, 33RD FLOOR
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10022
		BUSINESS PHONE:		212-752-5750

	MAIL ADDRESS:	
		STREET 1:		C/O VIEX CAPITAL ADVISORS, LLC
		STREET 2:		825 THIRD AVENUE, 33RD FLOOR
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10022

	FORMER NAME:	
		FORMER CONFORMED NAME:	VIEX Opportunities Fund, LP - Series One
		DATE OF NAME CHANGE:	20171212

	FORMER NAME:	
		FORMER CONFORMED NAME:	VIEX Special Opportunities Fund II, LP
		DATE OF NAME CHANGE:	20151228

	FORMER NAME:	
		FORMER CONFORMED NAME:	Vertex Special Opportunities Fund II, LP
		DATE OF NAME CHANGE:	20140910

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			VIEX Special Opportunities Fund III, LP
		CENTRAL INDEX KEY:			0001619126
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-36343
		FILM NUMBER:		201077413

	BUSINESS ADDRESS:	
		STREET 1:		C/O VIEX CAPITAL ADVISORS, LLC
		STREET 2:		825 THIRD AVENUE, 33RD FLOOR
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10022
		BUSINESS PHONE:		212-752-5750

	MAIL ADDRESS:	
		STREET 1:		C/O VIEX CAPITAL ADVISORS, LLC
		STREET 2:		825 THIRD AVENUE, 33RD FLOOR
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10022

	FORMER NAME:	
		FORMER CONFORMED NAME:	Vertex Special Opportunities Fund III, LP
		DATE OF NAME CHANGE:	20140910

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			VIEX GP, LLC
		CENTRAL INDEX KEY:			0001654852
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-36343
		FILM NUMBER:		201077414

	BUSINESS ADDRESS:	
		STREET 1:		825 THIRD AVE.
		STREET 2:		33RD FLOOR
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10022
		BUSINESS PHONE:		212-752-5750

	MAIL ADDRESS:	
		STREET 1:		825 THIRD AVE.
		STREET 2:		33RD FLOOR
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10022

	FORMER NAME:	
		FORMER CONFORMED NAME:	Vertex GP, LLC
		DATE OF NAME CHANGE:	20151005

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			VIEX Special Opportunities GP II, LLC
		CENTRAL INDEX KEY:			0001658891
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-36343
		FILM NUMBER:		201077415

	BUSINESS ADDRESS:	
		STREET 1:		825 THIRD AVENUE
		STREET 2:		33RD FLOOR
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10022
		BUSINESS PHONE:		212-752-5750

	MAIL ADDRESS:	
		STREET 1:		825 THIRD AVENUE
		STREET 2:		33RD FLOOR
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10022

	FORMER NAME:	
		FORMER CONFORMED NAME:	Vertex Special Opportunities GP II, LLC
		DATE OF NAME CHANGE:	20151119

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			VIEX Special Opportunities GP III, LLC
		CENTRAL INDEX KEY:			0001676049
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-36343
		FILM NUMBER:		201077416

	BUSINESS ADDRESS:	
		STREET 1:		825 THIRD AVE, 33RD FLOOR
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10022
		BUSINESS PHONE:		(212) 451-2282

	MAIL ADDRESS:	
		STREET 1:		825 THIRD AVE, 33RD FLOOR
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10022

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			VIEX Capital Advisors, LLC
		CENTRAL INDEX KEY:			0001619125
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-36343
		FILM NUMBER:		201077417

	BUSINESS ADDRESS:	
		STREET 1:		745 BOYLSTON STREET
		STREET 2:		3RD FLOOR
		CITY:			BOSTON
		STATE:			MA
		ZIP:			02116
		BUSINESS PHONE:		212-752-5750

	MAIL ADDRESS:	
		STREET 1:		745 BOYLSTON STREET
		STREET 2:		3RD FLOOR
		CITY:			BOSTON
		STATE:			MA
		ZIP:			02116

	FORMER NAME:	
		FORMER CONFORMED NAME:	Vertex Capital Advisors, LLC
		DATE OF NAME CHANGE:	20140910

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			A10 Networks, Inc.
		CENTRAL INDEX KEY:			0001580808
		STANDARD INDUSTRIAL CLASSIFICATION:	COMPUTER COMMUNICATIONS EQUIPMENT [3576]
		IRS NUMBER:				201446869
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		2300 ORCHARD PKWY
		CITY:			SAN JOSE
		STATE:			CA
		ZIP:			95131
		BUSINESS PHONE:		(408) 325-8668

	MAIL ADDRESS:	
		STREET 1:		2300 ORCHARD PKWY
		CITY:			SAN JOSE
		STATE:			CA
		ZIP:			95131
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>wf-form4_159665835222629.xml
<DESCRIPTION>FORM 4
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2020-08-03</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001580808</issuerCik>
        <issuerName>A10 Networks, Inc.</issuerName>
        <issuerTradingSymbol>ATEN</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001443284</rptOwnerCik>
            <rptOwnerName>Singer Eric</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O A10 NETWORKS, INC.</rptOwnerStreet1>
            <rptOwnerStreet2>2300 ORCHARD PARKWAY</rptOwnerStreet2>
            <rptOwnerCity>SAN JOSE</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>95131</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001606750</rptOwnerCik>
            <rptOwnerName>VIEX Opportunities Fund, LP Series One</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O A10 NETWORKS, INC.</rptOwnerStreet1>
            <rptOwnerStreet2>2300 ORCHARD PARKWAY</rptOwnerStreet2>
            <rptOwnerCity>SAN JOSE</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>95131</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>0001659404</rptOwnerCik>
            <rptOwnerName>VIEX Opportunities Fund, LP - Series Two</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O A10 NETWORKS, INC.</rptOwnerStreet1>
            <rptOwnerStreet2>2300 ORCHARD PARKWAY</rptOwnerStreet2>
            <rptOwnerCity>SAN JOSE</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>95131</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>0001619127</rptOwnerCik>
            <rptOwnerName>VIEX Special Opportunities Fund II, LP</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O A10 NETWORKS, INC.</rptOwnerStreet1>
            <rptOwnerStreet2>2300 ORCHARD PARKWAY</rptOwnerStreet2>
            <rptOwnerCity>SAN JOSE</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>95131</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>0001619126</rptOwnerCik>
            <rptOwnerName>VIEX Special Opportunities Fund III, LP</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O A10 NETWORKS, INC.</rptOwnerStreet1>
            <rptOwnerStreet2>2300 ORCHARD PARKWAY</rptOwnerStreet2>
            <rptOwnerCity>SAN JOSE</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>95131</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>0001654852</rptOwnerCik>
            <rptOwnerName>VIEX GP, LLC</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O A10 NETWORKS, INC.</rptOwnerStreet1>
            <rptOwnerStreet2>2300 ORCHARD PARKWAY</rptOwnerStreet2>
            <rptOwnerCity>SAN JOSE</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>95131</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>0001658891</rptOwnerCik>
            <rptOwnerName>VIEX Special Opportunities GP II, LLC</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O A10 NETWORKS, INC.</rptOwnerStreet1>
            <rptOwnerStreet2>2300 ORCHARD PARKWAY</rptOwnerStreet2>
            <rptOwnerCity>SAN JOSE</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>95131</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>0001676049</rptOwnerCik>
            <rptOwnerName>VIEX Special Opportunities GP III, LLC</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O A10 NETWORKS, INC.</rptOwnerStreet1>
            <rptOwnerStreet2>2300 ORCHARD PARKWAY</rptOwnerStreet2>
            <rptOwnerCity>SAN JOSE</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>95131</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>0001619125</rptOwnerCik>
            <rptOwnerName>VIEX Capital Advisors, LLC</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O A10 NETWORKS, INC.</rptOwnerStreet1>
            <rptOwnerStreet2>2300 ORCHARD PARKWAY</rptOwnerStreet2>
            <rptOwnerCity>SAN JOSE</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>95131</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock, par value $0.00001</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>56190</value>
                    <footnoteId id="F1"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                    <footnoteId id="F2"/>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock, par value $0.00001</value>
            </securityTitle>
            <transactionDate>
                <value>2020-08-03</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>J</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>123762</value>
                    <footnoteId id="F3"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>1534598</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By Viex Opportunities Fund, LP - Series One</value>
                    <footnoteId id="F2"/>
                    <footnoteId id="F4"/>
                    <footnoteId id="F5"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock, par value $0.00001</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>482877</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By Viex Opportunities Fund, LP - Series Two</value>
                    <footnoteId id="F2"/>
                    <footnoteId id="F5"/>
                    <footnoteId id="F6"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock, par value $0.00001</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>5255022</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By Viex Special Opportunities Fund II, LP</value>
                    <footnoteId id="F2"/>
                    <footnoteId id="F5"/>
                    <footnoteId id="F7"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock, par value $0.00001</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>487416</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By Viex Special Opportunities Fund III, LP</value>
                    <footnoteId id="F2"/>
                    <footnoteId id="F5"/>
                    <footnoteId id="F8"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">Certain shares are represented by Restricted Stock Units granted to Eric Singer in connection with his service on A10 Networks, Inc.'s (the &quot;Issuer&quot;) board of directors.</footnote>
        <footnote id="F2">This Form 4 is filed jointly by VIEX Opportunities Fund, LP - Series One (&quot;Series One&quot;), a series of VIEX Opportunities Fund, LP, VIEX Opportunities Fund, LP - Series Two (&quot;Series Two&quot;), a series of VIEX Opportunities Fund, LP, VIEX Special Opportunities Fund II, LP (&quot;VSO II&quot;), Viex Special Opportunities Fund III, LP (&quot;VSO III&quot;), VIEX GP, LLC (&quot;VIEX GP&quot;), VIEX Special Opportunities GP II, LLC (&quot;VSO GP II&quot;), Viex Special Opportunities GP III, LLC (&quot;VSO GP III&quot;), VIEX Capital Advisors, LLC (&quot;VIEX Capital&quot;), and Mr. Singer (collectively, the &quot;Reporting Persons&quot;).</footnote>
        <footnote id="F3">Represents a distribution of shares of the Issuer from Series One to a limited partner of Series One for no consideration.</footnote>
        <footnote id="F4">Securities of the Issuer beneficially owned directly by Series One. VIEX GP, as the general partner of Series One, may be deemed the beneficial owner of the securities of the Issuer beneficially owned by Series One. VIEX Capital, as the investment manager of Series One, may be deemed the beneficial owner of the securities of the Issuer beneficially owned by Series One. Mr. Singer, as the managing member of each of VIEX GP and VIEX Capital, may be deemed the beneficial owner of the securities of the Issuer beneficially owned by Series One.</footnote>
        <footnote id="F5">Each Reporting Person disclaims beneficial ownership of the securities of the Issuer reported herein except to the extent of his or its pecuniary interest therein, and the inclusion of these shares in this report shall not be deemed to be an admission that any Reporting Person is the beneficial owner of such securities for purposes of Section 16 or for any other purpose.</footnote>
        <footnote id="F6">Securities of the Issuer beneficially owned directly by Series Two. VIEX GP, as the general partner of Series Two, may be deemed the beneficial owner of the securities of the Issuer beneficially owned by Series Two. VIEX Capital, as the investment manager of Series Two, may be deemed the beneficial owner of the securities of the Issuer beneficially owned by Series Two. Mr. Singer, as the managing member of each of VIEX GP and VIEX Capital, may be deemed the beneficial owner of the securities of the Issuer beneficially owned by Series Two.</footnote>
        <footnote id="F7">Securities of the Issuer beneficially owned directly by VSO II. VSO GP II, as the general partner of VSO II, may be deemed the beneficial owner of the securities of the Issuer beneficially owned by VSO II. VIEX Capital, as the investment manager of VSO II, may be deemed the beneficial owner of the securities of the Issuer beneficially owned by VSO II. Mr. Singer, as the managing member of each of VSO GP II and VIEX Capital, may be deemed the beneficial owner of the securities of the Issuer beneficially owned by VSO II.</footnote>
        <footnote id="F8">Securities of the Issuer beneficially owned directly by VSO III. VSO GP III, as the general partner of VSO III, may be deemed the beneficial owner of the securities of the Issuer beneficially owned by VSO III. VIEX Capital, as the investment manager of VSO III, may be deemed the beneficial owner of the securities of the Issuer beneficially owned by VSO III. Mr. Singer, as the managing member of each of VSO GP III and VIEX Capital, may be deemed the beneficial owner of the securities of the Issuer beneficially owned by VSO III.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>ERIC SINGER, Name /s/ Eric Singer</signatureName>
        <signatureDate>2020-08-05</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>VIEX OPPORTUNITIES FUND, LP - SERIES ONE, By: VIEX GP, LLC, its General Partner, Name: /s/ Eric Singer, Title: Managing Member</signatureName>
        <signatureDate>2020-08-05</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>VIEX OPPORTUNITIES FUND, LP - SERIES TWO, By: VIEX GP, LLC, its General Partner, Name: /s/ Eric Singer, Title: Managing Member</signatureName>
        <signatureDate>2020-08-05</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>VIEX SPECIAL OPPORTUNITIES FUND II, LP, By: VIEX Special Opportunities GP II, LLC, its General Partner, Name: /s/ Eric Singer, Title: Managing Member</signatureName>
        <signatureDate>2020-08-05</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>VIEX SPECIAL OPPORTUNITIES FUND III, LP, By: VIEX Special Opportunities GP III, LLC, its General Partner, Name: /s/ Eric Singer, Title: Managing Member</signatureName>
        <signatureDate>2020-08-05</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>VIEX GP, LLC, Name: /s/ Eric Singer, Title: Managing Member</signatureName>
        <signatureDate>2020-08-05</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>VIEX SPECIAL OPPORTUNITIES GP II, LLC, Name: /s/ Eric Singer, Title: Managing Member</signatureName>
        <signatureDate>2020-08-05</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>VIEX SPECIAL OPPORTUNITIES GP III, LLC, Name: /s/ Eric Singer, Title: Managing Member</signatureName>
        <signatureDate>2020-08-05</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>VIEX CAPITAL ADVISORS, LLC, Name: /s/ Eric Singer, Title: Managing Member</signatureName>
        <signatureDate>2020-08-05</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
