<SEC-DOCUMENT>0001111928-21-000153.txt : 20210917
<SEC-HEADER>0001111928-21-000153.hdr.sgml : 20210917
<ACCEPTANCE-DATETIME>20210917162055
ACCESSION NUMBER:		0001111928-21-000153
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20210915
FILED AS OF DATE:		20210917
DATE AS OF CHANGE:		20210917

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			IP FIBRE DEVICES LTD
		CENTRAL INDEX KEY:			0001130423
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-33155
		FILM NUMBER:		211260675

	BUSINESS ADDRESS:	
		STREET 1:		C/O IPG PHOTONICS CORP
		STREET 2:		660 MAIN STREET
		CITY:			STURBRIDGE
		STATE:			MA
		ZIP:			01566
		BUSINESS PHONE:		5083476800

	MAIL ADDRESS:	
		STREET 1:		660 MAIN STREET
		CITY:			STURBRIDGE
		STATE:			MA
		ZIP:			01566

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			IPG PHOTONICS CORP
		CENTRAL INDEX KEY:			0001111928
		STANDARD INDUSTRIAL CLASSIFICATION:	SEMICONDUCTORS & RELATED DEVICES [3674]
		IRS NUMBER:				043444218
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		50 OLD WEBSTER ROAD
		CITY:			OXFORD
		STATE:			MA
		ZIP:			01540
		BUSINESS PHONE:		5083731100

	MAIL ADDRESS:	
		STREET 1:		50 OLD WEBSTER ROAD
		CITY:			OXFORD
		STATE:			MA
		ZIP:			01540
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>wf-form4_163191003284407.xml
<DESCRIPTION>FORM 4
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2021-09-15</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001111928</issuerCik>
        <issuerName>IPG PHOTONICS CORP</issuerName>
        <issuerTradingSymbol>IPGP</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001130423</rptOwnerCik>
            <rptOwnerName>IP FIBRE DEVICES LTD</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O IPG PHOTONICS CORPORATION</rptOwnerStreet1>
            <rptOwnerStreet2>50 OLD WEBSTER ROAD</rptOwnerStreet2>
            <rptOwnerCity>OXFORD</rptOwnerCity>
            <rptOwnerState>MA</rptOwnerState>
            <rptOwnerZipCode>01540</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2021-09-15</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>6944</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>171.91</value>
                    <footnoteId id="F2"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                    <footnoteId id="F1"/>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>6930260</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2021-09-15</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>5556</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>172.71</value>
                    <footnoteId id="F3"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                    <footnoteId id="F1"/>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>6924704</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2021-09-16</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>6661</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>170.24</value>
                    <footnoteId id="F4"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                    <footnoteId id="F1"/>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>6918043</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2021-09-16</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>4039</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>171.13</value>
                    <footnoteId id="F5"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                    <footnoteId id="F1"/>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>6914004</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">The sale reported in this Form 4 was effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on March 16, 2021.</footnote>
        <footnote id="F2">The reported transaction involves sale transactions ranging from $171.34 to $172.33 per share. The weighted average price per share was $171.91. The Reporting Person undertakes to provide upon request by the SEC staff, the Issuer or a security holder of the Issuer, information regarding the number of shares sold at each separate price.</footnote>
        <footnote id="F3">The reported transaction involves sale transactions ranging from $172.34 to $173.20 per share. The weighted average price per share was $172.71. The Reporting Person undertakes to provide upon request by the SEC staff, the Issuer or a security holder of the Issuer, information regarding the number of shares sold at each separate price.</footnote>
        <footnote id="F4">The reported transaction involves sale transactions ranging from $169.71 to $170.70 per share. The weighted average price per share was $170.24. The Reporting Person undertakes to provide upon request by the SEC staff, the Issuer or a security holder of the Issuer, information regarding the number of shares sold at each separate price.</footnote>
        <footnote id="F5">The reported transaction involves sale transactions ranging from $170.76 to $171.59 per share. The weighted average price per share was $171.13. The Reporting Person undertakes to provide upon request by the SEC staff, the Issuer or a security holder of the Issuer, information regarding the number of shares sold at each separate price.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Angelo P. Lopresti, Attorney-in-Fact</signatureName>
        <signatureDate>2021-09-17</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
