Exhibit 4.2

   

  SPECIMEN CLASS A ORDINARY SHARE CERTIFICATE 

   

  	
          NUMBER C–[ ] 

        	
           

        	
          SHARES

        
	
           

        	
           

        
	
          SEE REVERSE FOR CERTAIN DEFINITIONS

        	
           

        	
          CUSIP G4365A 101 

          

        


   

  HCM ACQUISITION CORP

   

  CLASS A ORDINARY SHARES 

   

  THIS CERTIFIES THAT is the owner of fully paid and non-assessable Class A ordinary shares, par value US$0.0001 per share, of HCM Acquisition Corp, a Cayman Islands
    exempted company (the “Company”), subject to the Company’s amended and restated memorandum and articles of association, as the same may be further amended, supplemented or otherwise modified from time to
    time, and transferable on the books of the Company in person or by duly authorized attorney upon surrender of this certificate properly endorsed.

   

  The Company will be forced to redeem all of its Class A ordinary shares if it is unable to complete a business combination within the period set forth in the
    Company’s amended and restated memorandum and articles of association, as the same may be further amended, supplemented or otherwise modified from time to time, all as more fully described in the Company’s final prospectus for its initial public
    offering, dated July [ ], 2021.

   

  This certificate is not valid unless countersigned by the Transfer Agent and registered by the Registrar of the Company.

   

  Witness the facsimile signatures of its duly authorized officers.

  	
          By:

        	
           

        	
           

        	
           

        	
           

        
	
           

        	
           

        	
          Chief Executive Officer

        	
           

        	
          Transfer Agent

        


   

  
     

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  HCM ACQUISITION CORP

   

  The Company will furnish without charge to each shareholder who so requests a statement of the powers, designations, preferences and relative, participating, optional
    or other special rights of each class of shares or series thereof of the Company and the qualifications, limitations, or restrictions of such preferences and/or rights.

   

  This certificate and the Class A ordinary shares represented thereby are issued and shall be held subject to all of the provisions of the Company’s amended and
    restated memorandum and articles of association, as the same may be further amended, supplemented or otherwise modified from time to time, and resolutions of the board of directors of the Company providing for the issue of the Class A ordinary shares
    (copies of which may be obtained from the Company), to all of which the holder of this certificate by acceptance hereof assents. The following abbreviations, when used in the inscription on the face of this certificate, shall be construed as though
    they were written out in full according to applicable laws or regulations:

  	
           

        	
           

        	
           

        	
           

        	
           

        	
           

        	
           

        	
           

        	
           

        	
           

        	
           

        	
           

        	
           

        
	
          TEN COM

        	
           

        	
          —

        	
           

        	
          as tenants in common

        	
           

        	
           

        	
           

        	
          UNIF

          GIFT

          MIN

          ACT

        	
           

        	
          —

        	
           

        	
          Custodian

        
	
           

        	
           

        	
           

        	
           

        	
           

        	
           

        	
           

        
	
           

        	
           

        	
           

        	
           

        	
           

        	
           

        	
           

        	
           

        	
           

        	
           

        	
           

        	
           

        	
          (Cust) (Minor)

        
	
           

        	
           

        	
           

        	
           

        	
           

        	
           

        	
           

        
	
          TEN ENT

        	
           

        	
          —

        	
           

        	
          as tenants by the entireties

        	
           

        	
           

        	
           

        	
           

        	
           

        	
           

        	
           

        	
          under Uniform Gifts to Minors Act

        
	
           

        	
           

        	
           

        	
           

        	
           

        	
           

        	
           

        
	
          JT TEN

        	
           

        	
          —

        	
           

        	
          as joint tenants with right of survivorship and not as tenants in common

        	
           

        	
           

        	
           

        	
           

        	
           

        	
           

        	
           

        	
          (State)

        


   

  Additional abbreviations may also be used though not in the above list.

   

  For value received, hereby sells, assigns and transfers unto 

   

  (PLEASE INSERT SOCIAL SECURITY OR OTHER IDENTIFYING NUMBER(S) OF ASSIGNEE(S))

   

  (PLEASE PRINT OR TYPEWRITE NAME(S) AND ADDRESS(ES), INCLUDING ZIP CODE, OF ASSIGNEE(S))

   

  Class A Ordinary Shares represented by the within Certificate, and does hereby irrevocably constitute and appoint Attorney to transfer the
        said Class A Ordinary Shares on the books of the within named Company with full power of substitution in the premises. 

  	
           

        	
           

        	
           

        	
           

        	
           

        
	
          Dated:

        	
           

        	
           

        	
           

        	
          Notice: The signature(s) to this assignment must correspond with the name as written upon the face of the certificate in
            every particular, without alteration or enlargement or any change whatever.

        


   

   

   

  
     

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  Signature(s) Guaranteed: 

  	
           

        
	
           

        	
           

        
	
          THE SIGNATURE(S) MUST BE GUARANTEED BY AN

        
	
          ELIGIBLE GUARANTOR INSTITUTION (BANKS,

        
	
          STOCKBROKERS, SAVINGS AND LOAN

        
	
          ASSOCIATIONS AND CREDIT UNIONS WITH

        
	
          MEMBERSHIP IN AN APPROVED SIGNATURE

        
	
          GUARANTEE MEDALLION PROGRAM, PURSUANT TO

        
	
          S.E.C. RULE 17Ad-15 UNDER THE SECURITIES

        
	
          EXCHANGE ACT OF 1934, AS AMENDED (OR ANY SUCCESSOR RULE).

        


   

  As more fully described in, and subject to the terms and conditions described in, the Company’s final prospectus for its initial public offering, dated [ ], 2021, the
    holder(s) of this certificate shall be entitled to receive a pro rata portion of certain funds held in the trust account established in connection with the Company’s initial public offering only in the event that (i) the Company redeems the Class A
    ordinary shares sold in its initial public offering and liquidates because it does not consummate an initial business combination within the period of time set forth in the Company’s amended and restated memorandum and articles of association (as the
    same may be further amended, supplemented or otherwise modified from time to time, the “amended and restated memorandum and articles of association”), (ii) the Company redeems the Class A ordinary shares
    sold in its initial public offering in connection with a shareholder vote to amend the amended and restated memorandum and articles of association (A) that would modify the substance or timing of the Company’s obligation to provide holders of the Class
    A ordinary shares the right to have their shares redeemed in connection with the Company’s initial business combination or to redeem 100% of the Class A ordinary shares if the Company does not complete its initial business combination within the time
    period set forth therein or (B) with respect to any other provision relating to the rights of holders of the Class A ordinary shares, or (iii) if the holder(s) seek(s) to redeem for cash his, her or its respective Class A ordinary shares in connection
    with a tender offer (or proxy solicitation, solely in the event the Company seeks shareholder approval of the proposed initial business combination) setting forth the details of a proposed initial business combination. In no other circumstances shall
    the holder(s) have any right or interest of any kind in or to the trust account.

   

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