<SEC-DOCUMENT>0002003074-25-000046.txt : 20251210
<SEC-HEADER>0002003074-25-000046.hdr.sgml : 20251210
<ACCEPTANCE-DATETIME>20251210202821
ACCESSION NUMBER:		0002003074-25-000046
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20251208
FILED AS OF DATE:		20251210
DATE AS OF CHANGE:		20251210

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Gibson Daniel Patrick
		CENTRAL INDEX KEY:			0001745725
		ORGANIZATION NAME:           	

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-37824
		FILM NUMBER:		251563266

	MAIL ADDRESS:	
		STREET 1:		400 FAIRVIEW AVENUE NORTH, SUITE 1200
		CITY:			SEATTLE
		STATE:			WA
		ZIP:			98109

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			SYLEBRA CAPITAL LLC
		CENTRAL INDEX KEY:			0002003074
		ORGANIZATION NAME:           	
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-37824
		FILM NUMBER:		251563267

	BUSINESS ADDRESS:	
		STREET 1:		3000 EL CAMINO REAL BUILDING 5 SUITE 450
		CITY:			PALO ALTO
		STATE:			CA
		ZIP:			94306
		BUSINESS PHONE:		(332) 242-8518

	MAIL ADDRESS:	
		STREET 1:		3000 EL CAMINO REAL BUILDING 5 SUITE 450
		CITY:			PALO ALTO
		STATE:			CA
		ZIP:			94306

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			IMPINJ INC
		CENTRAL INDEX KEY:			0001114995
		STANDARD INDUSTRIAL CLASSIFICATION:	ELECTRONIC COMPONENTS, NEC [3679]
		ORGANIZATION NAME:           	04 Manufacturing
		EIN:				912041398
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		400 FAIRVIEW AVENUE NORTH
		STREET 2:		SUITE 1200
		CITY:			SEATTLE
		STATE:			WA
		ZIP:			98109
		BUSINESS PHONE:		206-517-5300

	MAIL ADDRESS:	
		STREET 1:		400 FAIRVIEW AVENUE NORTH
		STREET 2:		SUITE 1200
		CITY:			SEATTLE
		STATE:			WA
		ZIP:			98109
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>primary_doc.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0508</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2025-12-08</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001114995</issuerCik>
        <issuerName>IMPINJ INC</issuerName>
        <issuerTradingSymbol>PI</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0002003074</rptOwnerCik>
            <rptOwnerName>SYLEBRA CAPITAL LLC</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>3000 EL CAMINO REAL BUILDING 5 SUITE 450</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>PALO ALTO</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>94306</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>1</isOther>
            <otherText>See Footnote</otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001745725</rptOwnerCik>
            <rptOwnerName>Gibson Daniel Patrick</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>400 FAIRVIEW AVENUE NORTH, SUITE 1200</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>SEATTLE</rptOwnerCity>
            <rptOwnerState>WA</rptOwnerState>
            <rptOwnerZipCode>98109</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <aff10b5One>0</aff10b5One>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2025-12-08</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>2494</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>160.7197</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>1497343</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See Footnote</value>
                    <footnoteId id="F1"/>
                    <footnoteId id="F2"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2025-12-09</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>40</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>160.0125</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>1497303</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See Footnote</value>
                    <footnoteId id="F1"/>
                    <footnoteId id="F2"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2025-12-10</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>84604</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>155.4929</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>1412699</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See Footnote</value>
                    <footnoteId id="F1"/>
                    <footnoteId id="F2"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">Sylebra Capital Limited (Sylebra HK) and Sylebra Capital LLC (Sylebra US) are the investment sub-advisers to Sylebra Capital Partners Master Fund, Ltd. (SCP MF),Sylebra Capital Menlo Master Fund (MENLO MF)and other advisory clients. Sylebra Capital Management (Sylebra Cayman) is the investment manager and parent of Sylebra HK.Sylebra Cayman owns 100% of the shares of Sylebra HK, and Daniel Patrick Gibson (Gibson) owns 100% of Class A shares of Sylebra Cayman and 100% of the share capital of Sylebra US. Gibson is a founder and Chief Investment Officer of Sylebra Cayman. In such capacities, Sylebra HK, Sylebra US, Sylebra Cayman and Gibson may bedeemed to share voting and dispositive power over the shares of common stock of the Issuer held by SCP MF, MENLO MF, and other advisory clients.</footnote>
        <footnote id="F2">These securities are held by SCP MF, MENLO MF, and/or other advisory clients. Gibson is a member of the board of directors of the Issuer. Sylebra HK, Sylebra US, Sylebra Cayman and Gibson disclaim beneficial ownership of these securities, and this report shall not be deemed an admission that Sylebra HK, Sylebra US,Sylebra Cayman and Gibson are the beneficial owners of such securities, except to the extent of their pecuniary interest, if any, therein.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>Matthew Whitehead, CCO, Authorsied Signatory</signatureName>
        <signatureDate>2025-12-10</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
