Exhibit 10.4


 


Amendment to Subscription Agreement


 


This Amendment (this
 “Amendment”), dated as of May 28, 2020, to that certain Subscription/Backstop Agreement, made and entered
into as of January 13, 2010 (the “Subscription Agreement”), is by and between
Mudrick Capital Acquisition Corporation, a Delaware corporation (the “Company”), and the undersigned
(“Subscriber”). Capitalized terms used but not otherwise defined herein shall have the meanings ascribed to
such terms in the Subscription Agreement.


 


WHEREAS, the parties
hereto desire to amend the Subscription Agreement to, among other things, increase the Total Subscription and, correspondingly,
increase the applicable purchase price for the Subscription; and


 


WHEREAS, Section 5.4
of the Subscription Agreement provides that the Subscription Agreement may not be modified, waived or terminated except by an instrument
in writing, signed by the party against whom enforcement of such modification, waiver, or termination is sought.


 


NOW, THEREFORE, in
consideration of the covenants and agreements set forth herein, the receipt and sufficiency of which are hereby acknowledged, the
parties hereto agree as follows:


 


1.            The
Total Subscription under the terms of the Subscription Agreement shall be [●].


 


2.            Section 1.1
of the Subscription Agreement is hereby amended by adding the following to the end of such provision: “; provided,
that to the extent the applicable purchase price (after giving effect to the adjustment as described above) would result in the
purchase of a fractional Share, then (x) the number of Shares to be purchased by Subscriber shall be rounded up to the nearest
whole number and (y) the applicable purchase price shall be correspondingly increased; provided, further, that
to the extent Subscriber would be entitled to a cash payment in lieu of fractional shares under Section 8.p. of that certain
Exchange Agreement, dated as of January 13, 2020, by and among the Corporation, Subscriber and the other signatories party
thereto (the “Exchange Agreement”), then (I) the applicable purchase price under the Subscription Agreement
shall be reduced by the amount of such cash payment in lieu of fractional shares and (II) Subscriber hereby waives the right
to receive any such cash payment in lieu of fractional shares thereunder.”


 


3.            Section 1.2
of the Subscription Agreement is hereby amended by adding the following to the end of the first sentence of such provision: “;
provided, that in the event the foregoing would result in the issuance of fractional Warrants to Subscriber, the number
of Warrants to be issued to Subscriber hereunder shall be rounded up to the nearest whole Warrant if such fraction is greater than
or equal to 0.5 and rounded down to the nearest whole number if such fraction is less than 0.5.”


 


4.            Subscriber
hereby (a) acknowledges and agrees that this Amendment shall be deemed to comply with the requirements regarding the delivery
of the Closing Notice as set forth in Section 3.1 of the Subscription Agreement and (b) waives any of the Company’s
obligations to the contrary. As such, on or prior to 9:30 a.m. Eastern Time on May 29, 2020, Subscriber shall deliver
to the Company $[●], representing payment for (i) [●] Shares and [●] Warrants, by wire transfer of United
States dollars in immediately available funds to the account specified in Annex A attached hereto. Following receipt of
such funds and in connection with the consummation of the Transaction, the Company shall deliver to the Subscriber the Shares and
the Warrants in book-entry form.


 






    


     


    

 


5.            The
Subscription Agreement as revised by this Amendment, together with the Exchange Agreement, as applicable, constitute the entire
agreement between the parties hereto with respect to the subject matter hereof and supersede all other prior and contemporaneous
agreements and understandings, both written and oral, between the parties hereto with respect to the subject matter hereof.


 


6.            This
Amendment, and any claim or cause of action hereunder based upon, arising out of or related to this Amendment (whether based on
law, in equity, in contract, in tort or any other theory) or the negotiation, execution, performance or enforcement of this Amendment
Agreement, shall be governed by and construed in accordance with the Laws of the State of Delaware, without giving effect to the
principles of conflicts of law thereof.


 


7.            Sections
5.1, 5.2, 5.4, 5.5, 5.6, 5.7, 5.9, 5.10, 5.11, 5.12, 5.13, 5.14, 5.15, 5.16, 5.17, 6 and 7 of the Subscription Agreement shall
apply to this Amendment, mutatis mutandis, as if set out herein.


 


8.            Except
as otherwise expressly amended or modified hereby, all of the terms and conditions of the Subscription Agreement shall continue
in full force and effect. Each reference to “hereof”, “hereunder”, “herein” and “hereby”
and each similar reference contained in the Subscription Agreement shall refer to the Subscription Agreement, as amended hereby.


 


[Signature page follows]


 






    


     


    

 


IN WITNESS WHEREOF,
each party hereto has caused this Amendment to be signed as of the date first written above.


 


	 	MUDRICK CAPITAL ACQUISITION CORPORATION
	 
	 	By:	 
	 
	 	 	 	Name:
	 
	 	 	 	Title:




 


[SIGNATURE PAGE
TO AMENDMENT TO SUBSCRIPTION AGREEMENT]


 






    


     


    

 


	 	SUBSCRIBER
	 
	 	By:	 
	 
	 	 	 	Name:
	 
	 	 	 	Title: