Exhibit 10.5

    

    

    THIS PROMISSORY NOTE (“NOTE”) HAS NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED (THE “SECURITIES ACT”). THIS NOTE HAS BEEN ACQUIRED FOR INVESTMENT ONLY AND MAY NOT BE SOLD, TRANSFERRED OR ASSIGNED IN
      THE ABSENCE OF REGISTRATION OF THE RESALE THEREOF UNDER THE SECURITIES ACT OR AN OPINION OF COUNSEL REASONABLY SATISFACTORY IN FORM, SCOPE AND SUBSTANCE TO THE COMPANY THAT SUCH REGISTRATION IS NOT REQUIRED.

    

    

    PROMISSORY NOTE

    

    

    	
            Principal Amount: up to $300,000

            (as set forth on the Schedule of Borrowings attached hereto)

          	
            Dated as of February 10, 2021

          


    

    

    HCM Acquisition Corp, a Cayman Islands exempted company (the “Maker”), promises to pay to the order of HCM Investor Holdings, LLC, a Delaware limited liability
      company, or its registered assigns or successors in interest (the “Payee”), or order, the principal sum of up to Three Hundred Thousand U.S. Dollars ($300,000) (as set forth on the Schedule of Borrowings
      attached hereto) in lawful money of the United States of America, on the terms and conditions described below. All payments on this Note shall be made by check or wire transfer of immediately available funds or as otherwise determined by the Maker to
      such account as the Payee may from time to time designate by written notice in accordance with the provisions of this Note.

     

    

    1.

    Principal. The principal balance of this Note shall be payable by the Maker on the earlier of: (i) December 31, 2021 or (ii) the date
      on which the Maker consummates an initial public offering of its securities (the “IPO”). The principal balance may be prepaid at any time. Under no circumstances shall any individual, including but not limited
      to any officer, director, employee or shareholder of the Maker, be obligated personally for any obligations or liabilities of the Maker hereunder.

    

    

    2.    

    Interest. No interest shall accrue on the unpaid principal balance of this Note.

    

    

    3.    

    Drawdown Requests. The Maker and the Payee agree that the Maker may request up to Three Hundred Thousand Dollars ($300,000) for costs
      reasonably related to the IPO. The principal of this Note may be drawn down from time to time prior to the earlier of: (i) December 31, 2021 or (ii) the date on which the Maker consummates the IPO, upon written request from the Maker to the Payee
      (each, a “Drawdown Request”). Each Drawdown Request must state the amount to be drawn down, and must not be an amount less than One Thousand Dollars ($1,000) unless agreed upon by the Maker and the Payee. The
      Payee shall fund each Drawdown Request no later than one (1) business day after receipt of a Drawdown Request; provided, however, that the maximum amount of drawdowns collectively under this Note is Three Hundred Thousand Dollars ($300,000). No fees,
      payments or other amounts shall be due to the Payee in connection with, or as a result of, any Drawdown Request by the Maker.

    

    

    4.    

    Application of Payments. All payments shall be applied first to payment in full of any costs incurred in the collection of any sum due
      under this Note, including (without limitation) reasonable attorney’s fees, then to the payment in full of any late charges and finally to the reduction of the unpaid principal balance of this Note.

    

    

    5.    

    Events of Default. Each of the following shall constitute an event of default (“Event of Default”):

    

    

    	

          	a.	
            Failure to Make Required Payments. Failure by the Maker to pay the principal amount due pursuant to this Note within five (5) business days of the date specified above.

          


    

    

    	

          	b.	
            Voluntary Bankruptcy, Etc. The commencement by the Maker of a voluntary case under any applicable bankruptcy, insolvency, reorganization, rehabilitation or other similar law, or the consent by it to the appointment of or taking
              possession by a receiver, liquidator, assignee, trustee, custodian, sequestrator (or other similar official) of the Maker or for any substantial part of its property, or the making by it of any assignment for the benefit of creditors, or the
              failure of the Maker generally to pay its debts as such debts become due, or the taking of corporate action by the Maker in furtherance of any of the foregoing.

          


    
      
        


    

    	

          	c.	
            Involuntary Bankruptcy, Etc. The entry of a decree or order for relief by a court having jurisdiction in the premises in respect of the Maker in an involuntary case under any applicable bankruptcy, insolvency or other similar law,
              or appointing a receiver, liquidator, assignee, custodian, trustee, sequestrator (or other similar official) of the Maker or for any substantial part of its property, or ordering the winding-up or liquidation of its affairs, and the
              continuance of any such decree or order unstayed and in effect for a period of 60 consecutive days.

          


    

    

    6.    

    Remedies.

    

    

    	

          	a.	
            Upon the occurrence of an Event of Default specified in Section 5(a) hereof, the Payee may, by written notice to the Maker, declare this Note to be due immediately and payable, whereupon the unpaid principal amount of this Note, and all
              other amounts payable thereunder, shall become immediately due and payable without presentment, demand, protest or other notice of any kind, all of which are hereby expressly waived, anything contained herein or in the documents evidencing
              the same to the contrary notwithstanding.

          


    

    

    	

          	b.	
            Upon the occurrence of an Event of Default specified in Sections 5(b) and 5(c) hereof, the unpaid principal balance of this Note, and all other sums payable with regard to this Note, shall automatically and immediately become due and
              payable, in all cases without any action on the part of the Payee.

          


    

    

    7.    

    Waivers. The Maker and all endorsers and guarantors of, and sureties for, this Note waive presentment for payment, demand, notice of
      dishonor, protest, and notice of protest with regard to this Note, all errors, defects and imperfections in any proceedings instituted by the Payee under the terms of this Note, and all benefits that might accrue to the Maker by virtue of any present
      or future laws exempting any property, real or personal, or any part of the proceeds arising from any sale of any such property, from attachment, levy or sale under execution, or providing for any stay of execution, exemption from civil process, or
      extension of time for payment; and the Maker agrees that any real estate that may be levied upon pursuant to a judgment obtained by virtue hereof, on any writ of execution issued hereon, may be sold upon any such writ in whole or in part in any order
      desired by the Payee.

    

    

    8.    

    Unconditional Liability. The Maker hereby waives all notices in connection with the delivery, acceptance, performance, default, or
      enforcement of the payment of this Note, and agrees that its liability shall be unconditional, without regard to the liability of any other party, and shall not be affected in any manner by any indulgence, extension of time, renewal, waiver or
      modification granted or consented to by the Payee, and consents to any and all extensions of time, renewals, waivers, or modifications that may be granted by the Payee with respect to the payment or other provisions of this Note, and agrees that
      additional makers, endorsers, guarantors, or sureties may become parties hereto without notice to the Maker or affecting the Maker’s liability hereunder.

    

    

    9.    

    Notices. All notices, statements or other documents which are required or contemplated by this Note shall be: (i) in writing and
      delivered personally or sent by first class registered or certified mail or overnight courier service to the address designated in writing, (ii) by facsimile to the number most recently provided to such party or such other address or fax number as
      may be designated in writing by such party and (iii) by electronic mail, to the electronic mail address most recently provided to such party or such other electronic mail address as may be designated in writing by such party. Any notice or other
      communication so transmitted shall be deemed to have been given on the day of delivery, if delivered personally, on the business day following receipt of written confirmation, if sent by facsimile or electronic transmission, and one (1) business day
      after delivery to an overnight courier service or five (5) days after mailing, if sent by mail.

    

    

    10.   

    Construction. THIS NOTE SHALL BE CONSTRUED AND ENFORCED IN ACCORDANCE WITH THE LAWS OF NEW YORK, WITHOUT REGARD TO CONFLICT OF LAW
      PROVISIONS THEREOF.

    

    

    11.   

    Severability. Any provision contained in this Note which is prohibited or unenforceable in any jurisdiction shall, as to such
      jurisdiction, be ineffective to the extent of such prohibition or unenforceability without invalidating the remaining provisions hereof, and any such prohibition or unenforceability in any jurisdiction shall not invalidate or render unenforceable
      such provision in any other jurisdiction.

    
      
        


    

    12.   

    Trust Waiver. Notwithstanding anything herein to the contrary, the Payee hereby waives any and all right, title, interest or claim of
      any kind (“Claim”) in or to any distribution of or from the trust account to be established in which the proceeds of the IPO conducted by the Maker (including the deferred underwriters discounts and
      commissions) and certain of the proceeds of the sale of the warrants issued in a private placement to occur in connection with the consummation of the IPO are to be deposited, as described in greater detail in the registration statement and
      prospectus to be filed with the Securities and Exchange Commission in connection with the IPO, and hereby agrees not to seek recourse, reimbursement, payment or satisfaction for any Claim against the trust account for any reason whatsoever.

    

    

    13.   

    Amendment; Waiver. Any amendment hereto or waiver of any provision hereof may be made with, and only with, the written consent of the
      Maker and the Payee.

    

    

    14.   

    Assignment. No assignment or transfer of this Note or any rights or obligations hereunder may be made by any party hereto (by operation
      of law or otherwise) without the prior written consent of the other party hereto and any attempted assignment without the required consent shall be void.

    

    

    [Signature page follows]

    
      
        


    

    IN WITNESS WHEREOF, the Maker, intending to be legally bound hereby, has caused this Note to be duly executed by the undersigned as of the day and year first above written.

    

    

    	 	
            HCM ACQUISITION CORP

          
	 	
            a Cayman Islands exempted company

          
	 	 	 
	 	
            By:

          	
            /s/ Shawn Matthews

          
	 	 	
            Name:

          	
            Shawn Matthews

          
	 	 	
            Title:

          	
            Chairman and Chief Executive Officer

          


    

    

    [Signature Page – Promissory Note Pre-IPO]

    
      
        


    

    SCHEDULE OF BORROWINGS

    

    

    The following increases or decreases in this Promissory Note have been made:

    

    

    	
            Date of Increase or

              Decrease

          	 	
            Amount of decrease in

              Principal Amount of this

              Promissory Note

          	 	
            Amount of increase in

              Principal Amount of this

              Promissory Note

          	 	
            Principal Amount of this

              Promissory Note following

              such decrease or increase