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

    <schemaVersion>X0508</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2024-03-20</periodOfReport>

    <notSubjectToSection16>true</notSubjectToSection16>

    <issuer>
        <issuerCik>0001845368</issuerCik>
        <issuerName>HCM Acquisition Corp</issuerName>
        <issuerTradingSymbol>HCMA</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001855118</rptOwnerCik>
            <rptOwnerName>Matthews Shawn</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O HCM ACQUISITION CORP</rptOwnerStreet1>
            <rptOwnerStreet2>100 FIRST STAMFORD PLACE, SUITE 330</rptOwnerStreet2>
            <rptOwnerCity>STAMFORD</rptOwnerCity>
            <rptOwnerState>CT</rptOwnerState>
            <rptOwnerZipCode>06902</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>true</isDirector>
            <isOfficer>true</isOfficer>
            <isTenPercentOwner>true</isTenPercentOwner>
            <officerTitle>Chairman and CEO</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001864019</rptOwnerCik>
            <rptOwnerName>HCM Investor Holdings, LLC</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O HCM INVESTOR HOLDINGS, LLC</rptOwnerStreet1>
            <rptOwnerStreet2>100 FIRST STAMFORD PLACE, SUITE 330</rptOwnerStreet2>
            <rptOwnerCity>STAMFORD</rptOwnerCity>
            <rptOwnerState>CT</rptOwnerState>
            <rptOwnerZipCode>06902</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isTenPercentOwner>true</isTenPercentOwner>
        </reportingOwnerRelationship>
    </reportingOwner>

    <aff10b5One>false</aff10b5One>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Class A Ordinary Shares</value>
            </securityTitle>
            <transactionDate>
                <value>2024-03-20</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>J</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>1250000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <footnoteId id="F1"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>8737500</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See Footnote</value>
                    <footnoteId id="F1"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Class A Ordinary Shares</value>
            </securityTitle>
            <transactionDate>
                <value>2024-03-20</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>J</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>8737500</value>
                </transactionShares>
                <transactionPricePerShare>
                    <footnoteId id="F2"/>
                    <footnoteId id="F3"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>0</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See Footnote</value>
                    <footnoteId id="F2"/>
                    <footnoteId id="F3"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Private Placement Warrants</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <footnoteId id="F4"/>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2024-03-20</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>D</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>10500000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <footnoteId id="F5"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F4"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F4"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Class A Ordinary Shares</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>10500000</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>0</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See Footnote</value>
                    <footnoteId id="F5"/>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">HCM Investor Holdings, LLC (the &quot;Sponsor&quot;) delivered 1,250,000 class A ordinary shares to certain vendors of Murano Global Investments PLC (&quot;Murano&quot;) immediately prior to the closing of the business combination pursuant to that certain Amended &amp; Restated Business Combination, dated August 2, 2023, as amended on December 31, 2023 (the &quot;Business Combination Agreement&quot;) in exchange for the satisfaction and cancellation of $12,500,000.00 in aggregate principal amount of amounts due from Murano pursuant to the Sponsor Support Agreement, dated August 2, 2023, by and among the Sponsor, holders of the Issuer's Class B ordinary shares, and Murano PV, S.A. de C.V, as amended on December 31, 2023 (the &quot;Sponsor Support Agreement&quot;).</footnote>
        <footnote id="F2">The reporting person disposed of all Issuer equity securities effective as of the consummation of the business combination and ceased to be a reporting person with respect to the Issuer.</footnote>
        <footnote id="F3">Pursuant to the Business Combination Agreement, each issued and outstanding share of the Issuer's ordinary shares automatically converted into the right to receive Murano ordinary shares on a one-to-one basis upon the consummation of such business combination.</footnote>
        <footnote id="F4">Each Private Placement Warrant is exercisable for one Class A ordinary share at a price of $11.50 per share. If the Issuer had not completed its business combination, the Private Placement Warrants would have expired worthless.</footnote>
        <footnote id="F5">The Sponsor forfeited its Private Placement Warrants in connection with the closing of the business combination pursuant to the Sponsor Support Agreement.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Shawn Matthews, by James Bond, Attorney-in-Fact</signatureName>
        <signatureDate>2024-03-22</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>/s/ HCM Investor Holdings, LLC, by James Bond, Attorney-in-Fact</signatureName>
        <signatureDate>2024-03-22</signatureDate>
    </ownerSignature>
</ownershipDocument>
