Exhibit 10.1


  


June 4, 2020


 


Mountain Crest Acquisition Corp


311 West 43rd Street, 12th Floor


New York, NY 10036


 


Chardan Capital Markets,
LLC


17 State Street, Suite 1600


New York, NY 10004


 


	 	Re:  	 Initial Public Offering



 


Gentlemen:


 


This letter is being
delivered to you in accordance with the Underwriting Agreement (the “Underwriting Agreement”) entered
into by and between Mountain Crest Acquisition Corp, a Delaware corporation (the “Company”), and Chardan
Capital Markets, LLC, as Representative (the “Representative”) of the several underwriters named on Schedule
A thereto (the “Underwriters”), relating to an underwritten initial public offering (the “IPO”)
of the Company’s units (the “Units”), each comprised of one share of common stock of the Company,
$.0001 par value (the “Common Stock”) and one right to receive one-tenth (1/10) of one share of Common
Stock (the “Rights”). Certain capitalized terms used herein are defined in paragraph 16 hereof.


 


In order to induce the
Company and the Underwriters to enter into the Underwriting Agreement and to proceed with the IPO, and in recognition of the benefit
that such IPO will confer upon the undersigned as a shareholder of the Company, and for other good and valuable consideration,
the receipt and sufficiency of which are hereby acknowledged, the undersigned hereby agrees with the Company as follows:


 


1.     
      If the Company solicits approval of its shareholders of a Business Combination, the undersigned will
vote all shares of Common Stock beneficially owned by him, her or it, whether acquired before, in or after the IPO, in favor of
such Business Combination.


 


2.           (a) 
Unless the Company’s shareholders are previously given the option to redeem their shares in connection with amending applicable
documents to extend the time that the Company has to complete a Business Combination and the Company fails to consummate a Business
Combination within 12 months from the closing of the Company’s IPO (or, in the event that the Company extended the period
of time to consummate a business combination up to three times, each by an additional three months, up to 21 months from the closing
of the Company’s IPO), the undersigned shall take all reasonable steps to (i) cause the Trust Fund to be liquidated and
distributed to the holders of the IPO Shares and (ii) cause the Company to liquidate as soon as reasonably practicable.


 


              (b) The
undersigned hereby waives any and all right, title, interest or claim of any kind in or to any distribution of the Trust Fund
and any remaining net assets of the Company as a result of such liquidation with respect to his, her or its Insider Shares including
any shares underlying the Private Units (“Claim”) and hereby waives any Claim the undersigned may have
in the future as a result of, or arising out of, any contracts or agreements with the Company and will not seek recourse against
the Trust Fund for any reason whatsoever.  The undersigned acknowledges and agrees that there will be no distribution from
the Trust Fund with respect to any Rights underlying the Private Units, all of which will terminate on the Company’s liquidation.


 


3.           Intentionally Omitted


 


4.           Intentionally Omitted


 


5.           The undersigned will escrow all of his, her or its Insider Shares pursuant to the terms of a Stock Escrow Agreement,
which the Company will enter into with the undersigned and an escrow agent acceptable to the Company.  After the underwriter
exercises its over-allotment option in full, the remaining portion of the underwriter’s over-allotment option is canceled,
or the underwriter’s over-allotment option terminates, the undersigned agrees to cancel a portion of the undersigned’s
Insider Shares such that the total number of Insider Shares equals (i) .25 multiplied by (ii) the number of Units sold in the IPO.


 


6.          The undersigned agrees that until the Company consummates a Business Combination, the undersigned’s
Private Units will be subject to the transfer restrictions described in the Subscription Agreement relating to the undersigned’s
Private Units.


 






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7.     
      In order to minimize potential conflicts of interest which may arise from multiple affiliations, the
undersigned agrees to present to the Company for its consideration, prior to presentation to any other person or entity, any suitable
opportunity to acquire a target business, until the earlier of the consummation by the Company of a Business Combination or the
liquidation of the Company, subject to any pre-existing fiduciary and contractual obligations the undersigned might have.


 


8.     
     The undersigned acknowledges and agrees that prior to entering into a Business Combination with a target business
that is affiliated with any Insiders of the Company or their affiliates, including any company that is a portfolio company of,
or otherwise affiliated with, or has received financial investment from, an entity with which any Insider or their affiliates is
affiliated, such transaction must be approved by a majority of the Company’s disinterested independent directors and the
Company must obtain an opinion from an independent investment banking firm that such Business Combination is fair to the Company’s
unaffiliated shareholders from a financial point of view.


 


9.     
      Neither the undersigned, any member of the family of the undersigned, nor any affiliate of the undersigned
will be entitled to receive and will not accept any compensation or other cash payment prior to, or for services rendered in connection
with, the consummation of the Business Combination; provided that the Company shall be allowed to repay working capital
loans made by the undersigned to the Company in cash upon consummation of the Business Combination.  Notwithstanding the
foregoing, the undersigned and any affiliate of the undersigned shall be entitled to reimbursement from the Company for their out-of-pocket
expenses incurred in connection with identifying, investigating and consummating a Business Combination.


 


10.         Neither the undersigned, any member of the family of the undersigned, nor any affiliate of the undersigned
will be entitled to receive or accept a finder’s fee or any other compensation in the event the undersigned, any member of
the family of the undersigned or any affiliate of the undersigned originates a Business Combination. 


 


11.       The undersigned agrees to be an officer and director of the Company until the earlier of the consummation by the
Company of a Business Combination or the liquidation of the Company.  The undersigned’s biographical information previously
furnished to the Company and the Representative is true and accurate in all material respects, does not omit any material information
with respect to the undersigned’s biography and contains all of the information required to be disclosed pursuant to Item
401 of Regulation S-K, promulgated under the Securities Act of 1933.  The undersigned’s FINRA Questionnaire previously
furnished to the Company and the Representative is true and accurate in all material respects.  The undersigned represents
and warrants that:


 


	 	(a)	He, she or it has never had a petition under the federal bankruptcy laws or any state insolvency law been filed by or against (i) him, her or it, or any partnership in which he or she was a general partner at or within two years before the time of filing; or (ii) any corporation or business association of which he or she was an executive officer at or within two years before the time of such filing;


 


	 	(b)	He, she or it has never had a receiver, fiscal agent or similar officer been appointed by a court for his business or property, or any such partnership;


 


	 	(c)	He, she or it has never been convicted of fraud in a civil or criminal proceeding;


 


	 	(d)	He, she or it has never been convicted in a criminal proceeding or named the subject of a pending criminal proceeding (excluding traffic violations and minor offenses);


 


	 	(e)	He, she or it has never been the subject of any order, judgment or decree, not subsequently reversed, suspended or vacated, of any court of competent jurisdiction, permanently or temporarily enjoining or otherwise limiting him, her or it from (i) acting as a futures commission merchant, introducing broker, commodity trading advisor, commodity pool operator, floor broker, leverage transaction merchant, any other person regulated by the Commodity Futures Trading Commission (“CFTC”) or an associated person of any of the foregoing, or as an investment adviser, underwriter, broker or dealer in securities, or as an affiliated person, director or employee of any investment company, bank, savings and loan association or insurance company, or from engaging in or continuing any conduct or practice in connection with any such activity; or (ii) engaging in any type of business practice; or (iii) engaging in any activity in connection with the purchase or sale of any security or commodity or in connection with any violation of federal or state securities or federal commodities laws;


 


	 	(f)	He, she, or it has never been the subject of any order, judgment or decree, not subsequently reversed, suspended or vacated, of any federal or state authority barring, suspending or otherwise limiting for more than 60 days his, her or its right to engage in any activity described in 11(e)(i) above, or to be associated with persons engaged in any such activity;


 






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	 	(g)	He, she, or it has never been found by a court of competent jurisdiction in a civil action or by the SEC to have violated any federal or state securities law, where the judgment in such civil action or finding by the SEC has not been subsequently reversed, suspended or vacated;


 


	 	(h)	He, she, or it has never been found by a court of competent jurisdiction in a civil action or by the CFTC to have violated any federal commodities law, where the judgment in such civil action or finding by the CFTC has not been subsequently reversed, suspended or vacated;


 


	 	(i)	He, she, or it has never been the subject of, or a party to, any Federal, State or foreign judicial or administrative order, judgment, decree or finding, not subsequently reversed, suspended or vacated, relating to an alleged violation of (i) any Federal, State or foreign securities or commodities law or regulation, (ii) any law or regulation respecting financial institutions or insurance companies including, but not limited to, a temporary or permanent injunction, order of disgorgement or restitution, civil money penalty or temporary or permanent cease-and desist order, or removal or prohibition order or (iii) any law or regulation prohibiting mail or wire fraud or fraud in connection with any business entity;


 


	 	(j)	He, she or it has never been the subject of, or party to, any sanction or order, not subsequently reversed, suspended or vacated, or any self-regulatory organization, any registered entity, or any equivalent exchange, association, entity or organization that has disciplinary authority over its members or persons associated with a member;


 


	 	(k)	He, she or it has never been convicted of any felony or misdemeanor: (i) in connection with the purchase or sale of any security; (ii) involving the making of any false filing with the SEC; or (iii) arising out of the conduct of the business of an underwriter, broker, dealer, municipal securities dealer, investment advisor or paid solicitor of purchasers of securities;


 


	 	(l)	He, she or it was never subject to a final order of a state or foreign  securities commission (or an agency of officer of a state performing like functions); a state or foreign authority that supervises or examines banks, savings associations, or credit unions; a state or foreign insurance commission (or an agency or officer of a state performing like functions); an appropriate federal or foreign banking agency; the CFTC; or the National Credit Union Administration that is based on a violation of any law or regulation that prohibits fraudulent, manipulative, or deceptive conduct;


  


	 	(m)	He, she or it has never been subject to any order, judgment or decree of any court of competent jurisdiction, that, at the time of the sale of the Units, restrained or enjoined him, her or it from engaging or continuing to engage in any conduct or practice: (i) in connection with the purchase or sale of any security; (ii) involving the making of any false filing with the SEC or any foreign regulatory agency with similar functions; or (iii) arising out of the conduct of the business of an underwriter, broker, dealer, municipal securities dealer, investment adviser or paid solicitor of purchasers of securities;


 


	 	(n)	He, she or it has never been subject to any order of the SEC or any foreign regulatory agency with similar functions that orders him, her or it to cease and desist from committing or causing a future violation of: (i) any scienter-based anti-fraud provision of the federal securities laws, including, but not limited to, Section 17(a)(1) of the Securities Act, Section 10(b) of the Exchange Act and Rule 10b-5 thereunder, Section 15(c) and Section 206(1) of the Advisers Act or any other rule or regulation thereunder; or (ii) Section 5 of the Securities Act;


 


	 	(o)	He, she or it has never filed (as a registrant or issuer), or been named as an underwriter in any registration statement or Regulation A offering statement filed with the SEC that was the subject of a refusal order, stop order, or order suspending the Regulation A exemption, or is, currently, the subject of an investigation or proceeding to determine whether a stop order or suspension order should be issued;


 


	 	(p)	He, she or it has never been subject to a United States Postal Service false representation order, or is currently subject to a temporary restraining order or preliminary injunction with respect to conduct alleged by the United States Postal Service to constitute a scheme or device for obtaining money or property through the mail by means of false representations;


 






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	 	(q)	He, she or it is not subject to a final order of a state securities commission (or an agency of officer of a state performing like functions); a state authority that supervises or examines banks, savings associations, or credit unions; a state insurance commission (or an agency or officer of a state performing like functions); an appropriate federal banking agency; the CFTC; or the National Credit Union Administration that bars the undersigned from: (i) association with an entity regulated by such commission, authority, agency or officer; (ii) engaging in the business of securities, insurance or banking; or (iii) engaging in savings association or credit union activities;


  


	 	(r)	He, she or it is not subject to an order of the SEC entered pursuant to section 15(b) or 15B(c) of the Securities Exchange Act of 1934 (the “Exchange Act”) or section 203(e) or 203(f) of the Investment Advisers Act of 1940 (the “Advisers Act”) that: (i) suspends or revokes the undersigned’s registration as a broker, dealer, municipal securities dealer or investment adviser; (ii) places limitations on the activities, functions or operations of, or imposes civil money penalties on, such person; or (iii) bars the undersigned from being associated with any entity or from participating in the offering of any penny stock; and


 


	 	(s)	He, she or it has never been suspended or expelled from membership in, or suspended or barred from association with a member of, a securities self-regulatory organization (e.g., a registered national securities exchange or a registered national or affiliated securities association) for any act or omission to act constituting conduct inconsistent with just and equitable principles of trade.


 


12.         The undersigned has full right and power, without violating any agreement by which he, she or it is bound, to enter into this letter
agreement and to serve as a Director and/or officer of the Company.


 


13.         The undersigned hereby waives his, her or its right to exercise redemption rights with respect to any shares of Common Stock owned
or to be owned by the undersigned, directly or indirectly, whether purchased by the undersigned prior to the IPO, in the IPO or
in the aftermarket, and agrees that he, she or it will not seek redemption with respect to or otherwise sell, such shares in connection
with any vote to approve a Business Combination with respect thereto, a vote to amend the provisions of the Company’s Amended
and Restated Certificate of Incorporation, or a tender offer by the Company prior to a Business Combination.


 


14.         The undersigned hereby agrees to not propose, or vote in favor of, an amendment to the Company’s Amended and Restated Certificate
of Incorporation with respect to the Company’s pre-Business Combination activities prior to the consummation of a Business
Combination unless the Company offers holders of IPO Shares the right to receive their pro rata portion of the funds then held
in the Trust Fund.


 


15.         In connection with Section 5-1401 of the General Obligations Law of the State of New York, this letter agreement shall be governed
by, and construed in accordance with, the laws of the State of New York without regard to principles of conflicts of law that would
result in the application of the substantive law of another jurisdiction.  The parties hereto agree that any action, proceeding
or claim arising out of or relating in any way to this letter agreement shall be resolved through final and binding arbitration
in accordance with the International Arbitration Rules of the American Arbitration Association (“AAA”).  The
arbitration shall be brought before the AAA International Center for Dispute Resolution’s offices in New York City, New York,
will be conducted in English and will be decided by a panel of three arbitrators selected from the AAA Commercial Disputes Panel
and that the arbitrator panel’s decision shall be final and enforceable by any court having jurisdiction over the party from
whom enforcement is sought.  The cost of such arbitrators and arbitration services, together with the prevailing party’s
legal fees and expenses, shall be borne by the non-prevailing party or as otherwise directed by the arbitrators. 


  


16.         As used herein, (i) a “Business Combination” shall mean a merger, share exchange, asset acquisition,
contractual arrangement, share purchase, recapitalization, reorganization or other similar business combination with one or more
businesses or entities; (ii) “Insiders” shall mean all officers, directors and shareholders of the Company
immediately prior to the IPO; (iii) “Insider Shares” shall mean all of the shares of Common Stock of
the Company acquired by an Insider prior to the IPO and any shares of Common Stock underlying the Private Units; (iv) “IPO
Shares” shall mean the shares of Common Stock issued in the Company’s IPO; (v) “Private Units”
shall mean (x) the Units purchased in the private placement taking place simultaneously with the consummation of the Company’s
IPO and (y) the additional Units that may be purchased in connection with the exercise of the over-allotment option by the underwriters
in the IPO as described in the Registration Statement; (vi) “Registration Statement” means the registration
statement on Form S-1 filed by the Company with respect to the IPO; and (vii) “Trust Fund” shall mean
the trust fund into which a portion of the net proceeds of the Company’s IPO will be deposited.


 


17.         Any notice, consent or request to be given in connection with any of the terms or provisions of this letter agreement shall be
in writing and shall be sent by express mail or similar private courier service, by certified mail (return receipt requested),
by hand delivery or facsimile transmission.


 






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If to the Representative:


 


Chardan Capital Markets, LLC


17 State
Street, Suite 1600


New York, NY 10004


Attn: George Kaufman


Facsimile: (646) 465-9039


 


with a copy (which copy shall not constitute
notice) to:


 


Scarinci Hollenbeck, LLC


3 Park Avenue, 15th Floor


New York, NY 10016


Attn: Dan Brecher


Fax No.: (212) 808-4155


 


If to the Company:


 


Mountain Crest Acquisition Corp


311 West 43rd Street, 12 Floor


New York, NY 10036


Attn:  Suying Liu,  Chief
Executive Officer


 


with a copy (which copy shall not constitute
notice) to:


 


Loeb & Loeb LLP


345 Park Avenue


New York, NY 10154


Attn: Giovanni Caruso, Esq.


Facsimile: (212) 504-3013


 


18.         No party hereto may assign either this letter agreement or any of its rights, interests, or obligations hereunder without the prior
written consent of the other party. Any purported assignment in violation of this paragraph shall be void and ineffectual and shall
not operate to transfer or assign any interest or title to the purported assignee. This letter agreement shall be binding on the
parties hereto and any successors and assigns thereof.


 


19.         The undersigned acknowledges and understands that the Underwriters and the Company will rely upon the agreements, representations
and warranties set forth herein in proceeding with the IPO.


 


[Signature Page Follows]


 






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        Sincerely,

        

	 	 
	 	By:	/s/ Dong Liu
	 	 	Name of Insider: Dong Liu


 


[SIGNATURE PAGE TO LETTER AGREEMENT]


 






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June 4, 2020


 


Mountain Crest Acquisition Corp


311 West 43rd Street, 12th Floor


New York, NY 10036


 


Chardan Capital Markets,
LLC


17 State Street, Suite 1600


New York, NY 10004


 





	 	Re:  	 Initial Public Offering


  


Gentlemen:


 


This letter is being
delivered to you in accordance with the Underwriting Agreement (the “Underwriting Agreement”) entered
into by and between Mountain Crest Acquisition Corp, a Delaware corporation (the “Company”), and Chardan
Capital Markets, LLC, as Representative (the “Representative”) of the several underwriters named on Schedule
A thereto (the “Underwriters”), relating to an underwritten initial public offering (the “IPO”)
of the Company’s units (the “Units”), each comprised of one share of common stock of the Company,
$.0001 par value (the “Common Stock”) and one right to receive one-tenth (1/10) of one share of Common
Stock (the “Rights”). Certain capitalized terms used herein are defined in paragraph 16 hereof.


 


In order to induce the
Company and the Underwriters to enter into the Underwriting Agreement and to proceed with the IPO, and in recognition of the benefit
that such IPO will confer upon the undersigned as a shareholder of the Company, and for other good and valuable consideration,
the receipt and sufficiency of which are hereby acknowledged, the undersigned hereby agrees with the Company as follows:


 


1.           If the Company solicits approval of its shareholders of a Business Combination, the undersigned will
vote all shares of Common Stock beneficially owned by him, her or it, whether acquired before, in or after the IPO, in favor of
such Business Combination.


 


2.           (a)  Unless the Company’s shareholders are previously given the option to redeem their shares
in connection with amending applicable documents to extend the time that the Company has to complete a Business Combination and
the Company fails to consummate a Business Combination within 12 months from the closing of the Company’s IPO (or, in the
event that the Company extended the period of time to consummate a business combination up to three times, each by an additional
three months, up to 21 months from the closing of the Company’s IPO), the undersigned shall take all reasonable steps to
(i) cause the Trust Fund to be liquidated and distributed to the holders of the IPO Shares and (ii) cause the Company to liquidate
as soon as reasonably practicable.


 


(b)         The undersigned hereby waives any and all right,
title, interest or claim of any kind in or to any distribution of the Trust Fund and any remaining net assets of the Company as
a result of such liquidation with respect to his, her or its Insider Shares including any shares underlying the Private Units
(“Claim”) and hereby waives any Claim the undersigned may have in the future as a result of, or arising
out of, any contracts or agreements with the Company and will not seek recourse against the Trust Fund for any reason whatsoever. 
The undersigned acknowledges and agrees that there will be no distribution from the Trust Fund with respect to any Rights underlying
the Private Units, all of which will terminate on the Company’s liquidation.


 


3.           Intentionally Omitted


 


4.           Intentionally Omitted


 


5.           The undersigned will escrow all of his, her or its Insider Shares pursuant to the terms of a Stock Escrow Agreement,
which the Company will enter into with the undersigned and an escrow agent acceptable to the Company.  After the underwriter
exercises its over-allotment option in full, the remaining portion of the underwriter’s over-allotment option is canceled,
or the underwriter’s over-allotment option terminates, the undersigned agrees to cancel a portion of the undersigned’s
Insider Shares such that the total number of Insider Shares equals (i) .25 multiplied by (ii) the number of Units sold in the IPO.


 


6.           The undersigned agrees that until the Company consummates a Business Combination, the undersigned’s
Private Units will be subject to the transfer restrictions described in the Subscription Agreement relating to the undersigned’s
Private Units.


 





7.           In
order to minimize potential conflicts of interest which may arise from multiple affiliations, the undersigned agrees to present
to the Company for its consideration, prior to presentation to any other person or entity, any suitable opportunity to acquire
a target business, until the earlier of the consummation by the Company of a Business Combination or the liquidation of the Company,
subject to any pre-existing fiduciary and contractual obligations the undersigned might have.


 






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8.           The undersigned acknowledges and agrees that prior to entering into a Business Combination with a target business
that is affiliated with any Insiders of the Company or their affiliates, including any company that is a portfolio company of,
or otherwise affiliated with, or has received financial investment from, an entity with which any Insider or their affiliates is
affiliated, such transaction must be approved by a majority of the Company’s disinterested independent directors and the
Company must obtain an opinion from an independent investment banking firm that such Business Combination is fair to the Company’s
unaffiliated shareholders from a financial point of view.


 


9.           Neither the undersigned, any member of the family of the undersigned, nor any affiliate of the undersigned
will be entitled to receive and will not accept any compensation or other cash payment prior to, or for services rendered in connection
with, the consummation of the Business Combination; provided that the Company shall be allowed to repay working capital
loans made by the undersigned to the Company in cash upon consummation of the Business Combination.  Notwithstanding the
foregoing, the undersigned and any affiliate of the undersigned shall be entitled to reimbursement from the Company for their out-of-pocket
expenses incurred in connection with identifying, investigating and consummating a Business Combination.


 


10.         Neither the undersigned, any member of the family of the undersigned, nor any affiliate of the undersigned
will be entitled to receive or accept a finder’s fee or any other compensation in the event the undersigned, any member of
the family of the undersigned or any affiliate of the undersigned originates a Business Combination. 


 


11.         The undersigned agrees to be a director of the Company until the earlier of the consummation by the Company of a
Business Combination or the liquidation of the Company.  The undersigned’s biographical information previously furnished
to the Company and the Representative is true and accurate in all material respects, does not omit any material information with
respect to the undersigned’s biography and contains all of the information required to be disclosed pursuant to Item 401
of Regulation S-K, promulgated under the Securities Act of 1933.  The undersigned’s FINRA Questionnaire previously
furnished to the Company and the Representative is true and accurate in all material respects.  The undersigned represents
and warrants that:


 


	 	(a)	He, she or it has never had a petition under the federal bankruptcy laws or any state insolvency law been filed by or against (i) him, her or it, or any partnership in which he or she was a general partner at or within two years before the time of filing; or (ii) any corporation or business association of which he or she was an executive officer at or within two years before the time of such filing;


 


	 	(b)	He, she or it has never had a receiver, fiscal agent or similar officer been appointed by a court for his business or property, or any such partnership;


 


	 	(c)	He, she or it has never been convicted of fraud in a civil or criminal proceeding;


 


	 	(d)	He, she or it has never been convicted in a criminal proceeding or named the subject of a pending criminal proceeding (excluding traffic violations and minor offenses);


 


	 	(e)	He, she or it has never been the subject of any order, judgment or decree, not subsequently reversed, suspended or vacated, of any court of competent jurisdiction, permanently or temporarily enjoining or otherwise limiting him, her or it from (i) acting as a futures commission merchant, introducing broker, commodity trading advisor, commodity pool operator, floor broker, leverage transaction merchant, any other person regulated by the Commodity Futures Trading Commission (“CFTC”) or an associated person of any of the foregoing, or as an investment adviser, underwriter, broker or dealer in securities, or as an affiliated person, director or employee of any investment company, bank, savings and loan association or insurance company, or from engaging in or continuing any conduct or practice in connection with any such activity; or (ii) engaging in any type of business practice; or (iii) engaging in any activity in connection with the purchase or sale of any security or commodity or in connection with any violation of federal or state securities or federal commodities laws;


 


	 	(f)	He, she, or it has never been the subject of any order, judgment or decree, not subsequently reversed, suspended or vacated, of any federal or state authority barring, suspending or otherwise limiting for more than 60 days his, her or its right to engage in any activity described in 11(e)(i) above, or to be associated with persons engaged in any such activity;


 






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	 	(g)	He, she, or it has never been found by a court of competent jurisdiction in a civil action or by the SEC to have violated any federal or state securities law, where the judgment in such civil action or finding by the SEC has not been subsequently reversed, suspended or vacated;


 


	 	(h)	He, she, or it has never been found by a court of competent jurisdiction in a civil action or by the CFTC to have violated any federal commodities law, where the judgment in such civil action or finding by the CFTC has not been subsequently reversed, suspended or vacated;


 


	 	(i)	He, she, or it has never been the subject of, or a party to, any Federal, State or foreign judicial or administrative order, judgment, decree or finding, not subsequently reversed, suspended or vacated, relating to an alleged violation of (i) any Federal, State or foreign securities or commodities law or regulation, (ii) any law or regulation respecting financial institutions or insurance companies including, but not limited to, a temporary or permanent injunction, order of disgorgement or restitution, civil money penalty or temporary or permanent cease-and desist order, or removal or prohibition order or (iii) any law or regulation prohibiting mail or wire fraud or fraud in connection with any business entity;


 


	 	(j)	He, she or it has never been the subject of, or party to, any sanction or order, not subsequently reversed, suspended or vacated, or any self-regulatory organization, any registered entity, or any equivalent exchange, association, entity or organization that has disciplinary authority over its members or persons associated with a member;


 


	 	(k)	He, she or it has never been convicted of any felony or misdemeanor: (i) in connection with the purchase or sale of any security; (ii) involving the making of any false filing with the SEC; or (iii) arising out of the conduct of the business of an underwriter, broker, dealer, municipal securities dealer, investment advisor or paid solicitor of purchasers of securities;


 


	 	(l)	He, she or it was never subject to a final order of a state or foreign  securities commission (or an agency of officer of a state performing like functions); a state or foreign authority that supervises or examines banks, savings associations, or credit unions; a state or foreign insurance commission (or an agency or officer of a state performing like functions); an appropriate federal or foreign banking agency; the CFTC; or the National Credit Union Administration that is based on a violation of any law or regulation that prohibits fraudulent, manipulative, or deceptive conduct;


  


	 	(m)	He, she or it has never been subject to any order, judgment or decree of any court of competent jurisdiction, that, at the time of the sale of the Units, restrained or enjoined him, her or it from engaging or continuing to engage in any conduct or practice: (i) in connection with the purchase or sale of any security; (ii) involving the making of any false filing with the SEC or any foreign regulatory agency with similar functions; or (iii) arising out of the conduct of the business of an underwriter, broker, dealer, municipal securities dealer, investment adviser or paid solicitor of purchasers of securities;


 


	 	(n)	He, she or it has never been subject to any order of the SEC or any foreign regulatory agency with similar functions that orders him, her or it to cease and desist from committing or causing a future violation of: (i) any scienter-based anti-fraud provision of the federal securities laws, including, but not limited to, Section 17(a)(1) of the Securities Act, Section 10(b) of the Exchange Act and Rule 10b-5 thereunder, Section 15(c) and Section 206(1) of the Advisers Act or any other rule or regulation thereunder; or (ii) Section 5 of the Securities Act;


 


	 	(o)	He, she or it has never filed (as a registrant or issuer), or been named as an underwriter in any registration statement or Regulation A offering statement filed with the SEC that was the subject of a refusal order, stop order, or order suspending the Regulation A exemption, or is, currently, the subject of an investigation or proceeding to determine whether a stop order or suspension order should be issued;


 


	 	(p)	He, she or it has never been subject to a United States Postal Service false representation order, or is currently subject to a temporary restraining order or preliminary injunction with respect to conduct alleged by the United States Postal Service to constitute a scheme or device for obtaining money or property through the mail by means of false representations;


 









    	 	3	 



     


    

 


	 	(q)	He, she or it is not subject to a final order of a state securities commission (or an agency of officer of a state performing like functions); a state authority that supervises or examines banks, savings associations, or credit unions; a state insurance commission (or an agency or officer of a state performing like functions); an appropriate federal banking agency; the CFTC; or the National Credit Union Administration that bars the undersigned from: (i) association with an entity regulated by such commission, authority, agency or officer; (ii) engaging in the business of securities, insurance or banking; or (iii) engaging in savings association or credit union activities;


  


	 	(r)	He, she or it is not subject to an order of the SEC entered pursuant to section 15(b) or 15B(c) of the Securities Exchange Act of 1934 (the “Exchange Act”) or section 203(e) or 203(f) of the Investment Advisers Act of 1940 (the “Advisers Act”) that: (i) suspends or revokes the undersigned’s registration as a broker, dealer, municipal securities dealer or investment adviser; (ii) places limitations on the activities, functions or operations of, or imposes civil money penalties on, such person; or (iii) bars the undersigned from being associated with any entity or from participating in the offering of any penny stock; and


 


	 	(s)	He, she or it has never been suspended or expelled from membership in, or suspended or barred from association with a member of, a securities self-regulatory organization (e.g., a registered national securities exchange or a registered national or affiliated securities association) for any act or omission to act constituting conduct inconsistent with just and equitable principles of trade.


 


12.         The undersigned has full right and power, without violating any agreement by which he, she or it is bound, to enter into this letter
agreement and to serve as a Director and/or officer of the Company.


 


13.         The undersigned hereby waives his, her or its right to exercise redemption rights with respect to any shares of Common Stock owned
or to be owned by the undersigned, directly or indirectly, whether purchased by the undersigned prior to the IPO, in the IPO or
in the aftermarket, and agrees that he, she or it will not seek redemption with respect to or otherwise sell, such shares in connection
with any vote to approve a Business Combination with respect thereto, a vote to amend the provisions of the Company’s Amended
and Restated Certificate of Incorporation, or a tender offer by the Company prior to a Business Combination.


 


14.         The undersigned hereby agrees to not propose, or vote in favor of, an amendment to the Company’s Amended and Restated Certificate
of Incorporation with respect to the Company’s pre-Business Combination activities prior to the consummation of a Business
Combination unless the Company offers holders of IPO Shares the right to receive their pro rata portion of the funds then held
in the Trust Fund.


 


15.         In connection with Section 5-1401 of the General Obligations Law of the State of New York, this letter agreement shall be governed
by, and construed in accordance with, the laws of the State of New York without regard to principles of conflicts of law that would
result in the application of the substantive law of another jurisdiction.  The parties hereto agree that any action, proceeding
or claim arising out of or relating in any way to this letter agreement shall be resolved through final and binding arbitration
in accordance with the International Arbitration Rules of the American Arbitration Association (“AAA”).  The
arbitration shall be brought before the AAA International Center for Dispute Resolution’s offices in New York City, New York,
will be conducted in English and will be decided by a panel of three arbitrators selected from the AAA Commercial Disputes Panel
and that the arbitrator panel’s decision shall be final and enforceable by any court having jurisdiction over the party from
whom enforcement is sought.  The cost of such arbitrators and arbitration services, together with the prevailing party’s
legal fees and expenses, shall be borne by the non-prevailing party or as otherwise directed by the arbitrators. 


  


16.         As used herein, (i) a “Business Combination” shall mean a merger, share exchange, asset acquisition,
contractual arrangement, share purchase, recapitalization, reorganization or other similar business combination with one or more
businesses or entities; (ii) “Insiders” shall mean all officers, directors and shareholders of the Company
immediately prior to the IPO; (iii) “Insider Shares” shall mean all of the shares of Common Stock of
the Company acquired by an Insider prior to the IPO and any shares of Common Stock underlying the Private Units; (iv) “IPO
Shares” shall mean the shares of Common Stock issued in the Company’s IPO; (v) “Private Units”
shall mean (x) the Units purchased in the private placement taking place simultaneously with the consummation of the Company’s
IPO and (y) the additional Units that may be purchased in connection with the exercise of the over-allotment option by the underwriters
in the IPO as described in the Registration Statement; (vi) “Registration Statement” means the registration
statement on Form S-1 filed by the Company with respect to the IPO; and (vii) “Trust Fund” shall mean
the trust fund into which a portion of the net proceeds of the Company’s IPO will be deposited.


 


17.         Any notice, consent or request to be given in connection with any of the terms or provisions of this letter agreement shall be
in writing and shall be sent by express mail or similar private courier service, by certified mail (return receipt requested),
by hand delivery or facsimile transmission.


 






    	 	4	 



     


    

 


If to the Representative:


 


Chardan Capital Markets, LLC





17 State Street, Suite 1600


New York, NY 10004


Attn: George Kaufman


Facsimile: (646) 465-9039


 


with a copy (which copy shall not constitute
notice) to:


 


Scarinci Hollenbeck, LLC


3 Park Avenue, 15th Floor


New York, NY 10016


Attn: Dan Brecher


Fax No.: (212) 808-4155


 


If to the Company:


 


Mountain Crest Acquisition Corp


311 West 43rd Street, 12 Floor


New York, NY 10036


Attn:  Suying Liu,  Chief
Executive Officer


 


with a copy (which copy shall not constitute
notice) to:


 


Loeb & Loeb LLP


345 Park Avenue


New York, NY 10154


Attn: Giovanni Caruso, Esq.


Facsimile: (212) 504-3013


 


18.         No party hereto may assign either this letter agreement or any of its rights, interests, or obligations hereunder without the prior
written consent of the other party. Any purported assignment in violation of this paragraph shall be void and ineffectual and shall
not operate to transfer or assign any interest or title to the purported assignee. This letter agreement shall be binding on the
parties hereto and any successors and assigns thereof.


 


19.         The undersigned acknowledges and understands that the Underwriters and the Company will rely upon the agreements, representations
and warranties set forth herein in proceeding with the IPO.


 


[Signature Page Follows]


 






    	 	5	 



     


    







 


	 	
        Sincerely,

	 	 
	 	By:	 /s/ Nelson Haight
	 	 	Name of Insider: Nelson Haight


  


[SIGNATURE PAGE TO LETTER AGREEMENT]


 






    	 	6	 



     


    

  


June 4, 2020


 


Mountain Crest Acquisition Corp


311 West 43rd Street, 12th Floor


New York, NY 10036


 


Chardan Capital Markets,
LLC


17 State Street, Suite 1600


New York, NY 10004


 





	 	Re:  	 Initial Public Offering


  


Gentlemen:


 


This letter is being
delivered to you in accordance with the Underwriting Agreement (the “Underwriting Agreement”) entered
into by and between Mountain Crest Acquisition Corp, a Delaware corporation (the “Company”), and Chardan
Capital Markets, LLC, as Representative (the “Representative”) of the several underwriters named on Schedule
A thereto (the “Underwriters”), relating to an underwritten initial public offering (the “IPO”)
of the Company’s units (the “Units”), each comprised of one share of common stock of the Company,
$.0001 par value (the “Common Stock”) and one right to receive one-tenth (1/10) of one share of Common
Stock (the “Rights”). Certain capitalized terms used herein are defined in paragraph 16 hereof.


 


In order to induce the
Company and the Underwriters to enter into the Underwriting Agreement and to proceed with the IPO, and in recognition of the benefit
that such IPO will confer upon the undersigned as a shareholder of the Company, and for other good and valuable consideration,
the receipt and sufficiency of which are hereby acknowledged, the undersigned hereby agrees with the Company as follows:


 


1.           If the Company solicits approval of its shareholders of a Business Combination, the undersigned will
vote all shares of Common Stock beneficially owned by him, her or it, whether acquired before, in or after the IPO, in favor of
such Business Combination.


 


2.           (a)  Unless the Company’s shareholders are previously given the option to redeem their shares
in connection with amending applicable documents to extend the time that the Company has to complete a Business Combination and
the Company fails to consummate a Business Combination within 12 months from the closing of the Company’s IPO (or, in the
event that the Company extended the period of time to consummate a business combination up to three times, each by an additional
three months, up to 21 months from the closing of the Company’s IPO), the undersigned shall take all reasonable steps to
(i) cause the Trust Fund to be liquidated and distributed to the holders of the IPO Shares and (ii) cause the Company to liquidate
as soon as reasonably practicable.


  


              (b) The undersigned
hereby waives any and all right, title, interest or claim of any kind in or to any distribution of the Trust Fund and any remaining
net assets of the Company as a result of such liquidation with respect to his, her or its Insider Shares including any shares underlying
the Private Units (“Claim”) and hereby waives any Claim the undersigned may have in the future as a result
of, or arising out of, any contracts or agreements with the Company and will not seek recourse against the Trust Fund for any reason
whatsoever.  The undersigned acknowledges and agrees that there will be no distribution from the Trust Fund with respect
to any Rights underlying the Private Units, all of which will terminate on the Company’s liquidation.


 


3.           Intentionally Omitted


 


4.           Intentionally
Omitted


 






    	 	1	 



     


    

 







5.           The undersigned will escrow all of his, her or its Insider Shares pursuant to the terms of a Stock Escrow Agreement,
which the Company will enter into with the undersigned and an escrow agent acceptable to the Company.  After the underwriter
exercises its over-allotment option in full, the remaining portion of the underwriter’s over-allotment option is canceled,
or the underwriter’s over-allotment option terminates, the undersigned agrees to cancel a portion of the undersigned’s
Insider Shares such that the total number of Insider Shares equals (i) .25 multiplied by (ii) the number of Units sold in the IPO.


 


6.           The undersigned agrees that until the Company consummates a Business Combination, the undersigned’s
Private Units will be subject to the transfer restrictions described in the Subscription Agreement relating to the undersigned’s
Private Units.





 


7.           In order to minimize potential conflicts of interest which may arise from multiple affiliations, the
undersigned agrees to present to the Company for its consideration, prior to presentation to any other person or entity, any suitable
opportunity to acquire a target business, until the earlier of the consummation by the Company of a Business Combination or the
liquidation of the Company, subject to any pre-existing fiduciary and contractual obligations the undersigned might have.


 


8.           The undersigned acknowledges and agrees that prior to entering into a Business Combination with a target business
that is affiliated with any Insiders of the Company or their affiliates, including any company that is a portfolio company of,
or otherwise affiliated with, or has received financial investment from, an entity with which any Insider or their affiliates is
affiliated, such transaction must be approved by a majority of the Company’s disinterested independent directors and the
Company must obtain an opinion from an independent investment banking firm that such Business Combination is fair to the Company’s
unaffiliated shareholders from a financial point of view.


 


9.           Neither the undersigned, any member of the family of the undersigned, nor any affiliate of the undersigned
will be entitled to receive and will not accept any compensation or other cash payment prior to, or for services rendered in connection
with, the consummation of the Business Combination; provided that the Company shall be allowed to repay working capital
loans made by the undersigned to the Company in cash upon consummation of the Business Combination.  Notwithstanding the
foregoing, the undersigned and any affiliate of the undersigned shall be entitled to reimbursement from the Company for their out-of-pocket
expenses incurred in connection with identifying, investigating and consummating a Business Combination.


 


10.         Neither the undersigned, any member of the family of the undersigned, nor any affiliate of the undersigned
will be entitled to receive or accept a finder’s fee or any other compensation in the event the undersigned, any member of
the family of the undersigned or any affiliate of the undersigned originates a Business Combination. 


 


11.         The undersigned agrees to be an officer and director of the Company until the earlier of the consummation by the
Company of a Business Combination or the liquidation of the Company.  The undersigned’s biographical information previously
furnished to the Company and the Representative is true and accurate in all material respects, does not omit any material information
with respect to the undersigned’s biography and contains all of the information required to be disclosed pursuant to Item
401 of Regulation S-K, promulgated under the Securities Act of 1933.  The undersigned’s FINRA Questionnaire previously
furnished to the Company and the Representative is true and accurate in all material respects.  The undersigned represents
and warrants that:


 


	 	(a)	He, she or it has never had a petition under the federal bankruptcy laws or any state insolvency law been filed by or against (i) him, her or it, or any partnership in which he or she was a general partner at or within two years before the time of filing; or (ii) any corporation or business association of which he or she was an executive officer at or within two years before the time of such filing;


 






    	 	2	 



     


    

 







	 	(b)	He, she or it has never had a receiver, fiscal agent or similar officer been appointed by a court for his business or property, or any such partnership;


 


	 	(c)	He, she or it has never been convicted of fraud in a civil or criminal proceeding;


 


	 	(d)	He, she or it has never been convicted in a criminal proceeding or named the subject of a pending criminal proceeding (excluding traffic violations and minor offenses);


 


	 	(e)	He, she or it has never been the subject of any order, judgment or decree, not subsequently reversed, suspended or vacated, of any court of competent jurisdiction, permanently or temporarily enjoining or otherwise limiting him, her or it from (i) acting as a futures commission merchant, introducing broker, commodity trading advisor, commodity pool operator, floor broker, leverage transaction merchant, any other person regulated by the Commodity Futures Trading Commission (“CFTC”) or an associated person of any of the foregoing, or as an investment adviser, underwriter, broker or dealer in securities, or as an affiliated person, director or employee of any investment company, bank, savings and loan association or insurance company, or from engaging in or continuing any conduct or practice in connection with any such activity; or (ii) engaging in any type of business practice; or (iii) engaging in any activity in connection with the purchase or sale of any security or commodity or in connection with any violation of federal or state securities or federal commodities laws;


 


	 	(f)	He, she, or it has never been the subject of any order, judgment or decree, not subsequently reversed, suspended or vacated, of any federal or state authority barring, suspending or otherwise limiting for more than 60 days his, her or its right to engage in any activity described in 11(e)(i) above, or to be associated with persons engaged in any such activity;


 







	 	(g)	He, she, or it has never been found by a court of competent jurisdiction in a civil action or by the SEC to have violated any federal or state securities law, where the judgment in such civil action or finding by the SEC has not been subsequently reversed, suspended or vacated;


 


	 	(h)	He, she, or it has never been found by a court of competent jurisdiction in a civil action or by the CFTC to have violated any federal commodities law, where the judgment in such civil action or finding by the CFTC has not been subsequently reversed, suspended or vacated;


 


	 	(i)	He, she, or it has never been the subject of, or a party to, any Federal, State or foreign judicial or administrative order, judgment, decree or finding, not subsequently reversed, suspended or vacated, relating to an alleged violation of (i) any Federal, State or foreign securities or commodities law or regulation, (ii) any law or regulation respecting financial institutions or insurance companies including, but not limited to, a temporary or permanent injunction, order of disgorgement or restitution, civil money penalty or temporary or permanent cease-and desist order, or removal or prohibition order or (iii) any law or regulation prohibiting mail or wire fraud or fraud in connection with any business entity;


 


	 	(j)	He, she or it has never been the subject of, or party to, any sanction or order, not subsequently reversed, suspended or vacated, or any self-regulatory organization, any registered entity, or any equivalent exchange, association, entity or organization that has disciplinary authority over its members or persons associated with a member;


 


	 	(k)	He, she or it has never been convicted of any felony or misdemeanor: (i) in connection with the purchase or sale of any security; (ii) involving the making of any false filing with the SEC; or (iii) arising out of the conduct of the business of an underwriter, broker, dealer, municipal securities dealer, investment advisor or paid solicitor of purchasers of securities;


 


	 	(l)	He, she or it was never subject to a final order of a state or foreign  securities commission (or an agency of officer of a state performing like functions); a state or foreign authority that supervises or examines banks, savings associations, or credit unions; a state or foreign insurance commission (or an agency or officer of a state performing like functions); an appropriate federal or foreign banking agency; the CFTC; or the National Credit Union Administration that is based on a violation of any law or regulation that prohibits fraudulent, manipulative, or deceptive conduct;


  






    	 	3	 



     


    

 


	 	(m)	He, she or it has never been subject to any order, judgment or decree of any court of competent jurisdiction, that, at the time of the sale of the Units, restrained or enjoined him, her or it from engaging or continuing to engage in any conduct or practice: (i) in connection with the purchase or sale of any security; (ii) involving the making of any false filing with the SEC or any foreign regulatory agency with similar functions; or (iii) arising out of the conduct of the business of an underwriter, broker, dealer, municipal securities dealer, investment adviser or paid solicitor of purchasers of securities;


 


	 	(n)	He, she or it has never been subject to any order of the SEC or any foreign regulatory agency with similar functions that orders him, her or it to cease and desist from committing or causing a future violation of: (i) any scienter-based anti-fraud provision of the federal securities laws, including, but not limited to, Section 17(a)(1) of the Securities Act, Section 10(b) of the Exchange Act and Rule 10b-5 thereunder, Section 15(c) and Section 206(1) of the Advisers Act or any other rule or regulation thereunder; or (ii) Section 5 of the Securities Act;


 


	 	(o)	He, she or it has never filed (as a registrant or issuer), or been named as an underwriter in any registration statement or Regulation A offering statement filed with the SEC that was the subject of a refusal order, stop order, or order suspending the Regulation A exemption, or is, currently, the subject of an investigation or proceeding to determine whether a stop order or suspension order should be issued;


 


	 	(p)	He, she or it has never been subject to a United States Postal Service false representation order, or is currently subject to a temporary restraining order or preliminary injunction with respect to conduct alleged by the United States Postal Service to constitute a scheme or device for obtaining money or property through the mail by means of false representations;


 


	 	(q)	He, she or it is not subject to a final order of a state securities commission (or an agency of officer of a state performing like functions); a state authority that supervises or examines banks, savings associations, or credit unions; a state insurance commission (or an agency or officer of a state performing like functions); an appropriate federal banking agency; the CFTC; or the National Credit Union Administration that bars the undersigned from: (i) association with an entity regulated by such commission, authority, agency or officer; (ii) engaging in the business of securities, insurance or banking; or (iii) engaging in savings association or credit union activities;


  


	 	(r)	He, she or it is not subject to an order of the SEC entered pursuant to section 15(b) or 15B(c) of the Securities Exchange Act of 1934 (the “Exchange Act”) or section 203(e) or 203(f) of the Investment Advisers Act of 1940 (the “Advisers Act”) that: (i) suspends or revokes the undersigned’s registration as a broker, dealer, municipal securities dealer or investment adviser; (ii) places limitations on the activities, functions or operations of, or imposes civil money penalties on, such person; or (iii) bars the undersigned from being associated with any entity or from participating in the offering of any penny stock; and


 


	 	(s)	He, she or it has never been suspended or expelled from membership in, or suspended or barred from association with a member of, a securities self-regulatory organization (e.g., a registered national securities exchange or a registered national or affiliated securities association) for any act or omission to act constituting conduct inconsistent with just and equitable principles of trade.


 


12.         The undersigned has full right and power, without violating any agreement by which he, she or it is bound, to enter into this letter
agreement and to serve as a Director and/or officer of the Company.


 


13.         The undersigned hereby waives his, her or its right to exercise redemption rights with respect to any shares of Common Stock owned
or to be owned by the undersigned, directly or indirectly, whether purchased by the undersigned prior to the IPO, in the IPO or
in the aftermarket, and agrees that he, she or it will not seek redemption with respect to or otherwise sell, such shares in connection
with any vote to approve a Business Combination with respect thereto, a vote to amend the provisions of the Company’s Amended
and Restated Certificate of Incorporation, or a tender offer by the Company prior to a Business Combination.


 


14.         The undersigned hereby agrees to not propose, or vote in favor of, an amendment to the Company’s Amended and Restated Certificate
of Incorporation with respect to the Company’s pre-Business Combination activities prior to the consummation of a Business
Combination unless the Company offers holders of IPO Shares the right to receive their pro rata portion of the funds then held
in the Trust Fund.


 






    	 	4	 



     


    

 


15.         In connection with Section 5-1401 of the General Obligations Law of the State of New York, this letter agreement shall be governed
by, and construed in accordance with, the laws of the State of New York without regard to principles of conflicts of law that would
result in the application of the substantive law of another jurisdiction.  The parties hereto agree that any action, proceeding
or claim arising out of or relating in any way to this letter agreement shall be resolved through final and binding arbitration
in accordance with the International Arbitration Rules of the American Arbitration Association (“AAA”).  The
arbitration shall be brought before the AAA International Center for Dispute Resolution’s offices in New York City, New York,
will be conducted in English and will be decided by a panel of three arbitrators selected from the AAA Commercial Disputes Panel
and that the arbitrator panel’s decision shall be final and enforceable by any court having jurisdiction over the party from
whom enforcement is sought.  The cost of such arbitrators and arbitration services, together with the prevailing party’s
legal fees and expenses, shall be borne by the non-prevailing party or as otherwise directed by the arbitrators. 


  


16.         As used herein, (i) a “Business Combination” shall mean a merger, share exchange, asset acquisition,
contractual arrangement, share purchase, recapitalization, reorganization or other similar business combination with one or more
businesses or entities; (ii) “Insiders” shall mean all officers, directors and shareholders of the Company
immediately prior to the IPO; (iii) “Insider Shares” shall mean all of the shares of Common Stock of
the Company acquired by an Insider prior to the IPO and any shares of Common Stock underlying the Private Units; (iv) “IPO
Shares” shall mean the shares of Common Stock issued in the Company’s IPO; (v) “Private Units”
shall mean (x) the Units purchased in the private placement taking place simultaneously with the consummation of the Company’s
IPO and (y) the additional Units that may be purchased in connection with the exercise of the over-allotment option by the underwriters
in the IPO as described in the Registration Statement; (vi) “Registration Statement” means the registration
statement on Form S-1 filed by the Company with respect to the IPO; and (vii) “Trust Fund” shall mean
the trust fund into which a portion of the net proceeds of the Company’s IPO will be deposited.


 


17.         Any notice, consent or request to be given in connection with any of the terms or provisions of this letter agreement shall be
in writing and shall be sent by express mail or similar private courier service, by certified mail (return receipt requested),
by hand delivery or facsimile transmission.


 


If to the Representative:


 


Chardan Capital Markets, LLC





17 State Street, Suite 1600


New York, NY 10004


Attn: George Kaufman


Facsimile: (646) 465-9039


 


with a copy (which copy shall not constitute
notice) to:


 


Scarinci Hollenbeck, LLC


3 Park Avenue, 15th Floor


New York, NY 10016


Attn: Dan Brecher


Fax No.: (212) 808-4155


 


If to the Company:


 


Mountain Crest Acquisition Corp


311 West 43rd Street, 12 Floor


New York, NY 10036


Attn:  Suying Liu,  Chief
Executive Officer


 


with a copy (which copy shall not constitute
notice) to:


 


Loeb & Loeb LLP


345 Park Avenue


New York, NY 10154


Attn: Giovanni Caruso, Esq.


Facsimile: (212) 504-3013


 


18.         No party hereto may assign either this letter agreement or any of its rights, interests, or obligations hereunder without the prior
written consent of the other party. Any purported assignment in violation of this paragraph shall be void and ineffectual and shall
not operate to transfer or assign any interest or title to the purported assignee. This letter agreement shall be binding on the
parties hereto and any successors and assigns thereof.


 


19.         The undersigned acknowledges and understands that the Underwriters and the Company will rely upon the agreements, representations
and warranties set forth herein in proceeding with the IPO.


 


[Signature Page Follows]


 






    	 	5	 



     


    

 


	 	
        Sincerely,

	 	 
	 	By:	 /s/ Suying Liu
	 	 	Name of Insider: Suying Liu


 


[SIGNATURE PAGE TO LETTER AGREEMENT]


 






    	 	6	 



     


    







  






 


 


June 4, 2020


 


Mountain Crest Acquisition Corp


311 West 43rd Street, 12th Floor


New York, NY 10036


 


Chardan Capital Markets,
LLC


17 State Street, Suite 1600


New York, NY 10004


 


           
             Re:       Initial
Public Offering


 


Gentlemen:


 


This letter is being
delivered to you in accordance with the Underwriting Agreement (the “Underwriting Agreement”) entered
into by and between Mountain Crest Acquisition Corp, a Delaware corporation (the “Company”), and Chardan
Capital Markets, LLC, as Representative (the “Representative”) of the several underwriters named on Schedule
A thereto (the “Underwriters”), relating to an underwritten initial public offering (the “IPO”)
of the Company’s units (the “Units”), each comprised of one share of common stock of the Company,
$.0001 par value (the “Common Stock”) and one right to receive one-tenth (1/10) of one share of Common
Stock (the “Rights”). Certain capitalized terms used herein are defined in paragraph 16 hereof.


 


In order to induce the
Company and the Underwriters to enter into the Underwriting Agreement and to proceed with the IPO, and in recognition of the benefit
that such IPO will confer upon the undersigned as a shareholder of the Company, and for other good and valuable consideration,
the receipt and sufficiency of which are hereby acknowledged, the undersigned hereby agrees with the Company as follows:


 


1.     
      If the Company solicits approval of its shareholders of a Business Combination, the undersigned will
vote all shares of Common Stock beneficially owned by him, her or it, whether acquired before, in or after the IPO, in favor of
such Business Combination.


 


2.      
     (a)  Unless the Company’s shareholders are previously given the option to redeem their shares
in connection with amending applicable documents to extend the time that the Company has to complete a Business Combination and
the Company fails to consummate a Business Combination within 12 months from the closing of the Company’s IPO (or, in the
event that the Company extended the period of time to consummate a business combination up to three times, each by an additional
three months, up to 21 months from the closing of the Company’s IPO), the undersigned shall take all reasonable steps to
(i) cause the Trust Fund to be liquidated and distributed to the holders of the IPO Shares and (ii) cause the Company to liquidate
as soon as reasonably practicable.


  


(b) The undersigned
hereby waives any and all right, title, interest or claim of any kind in or to any distribution of the Trust Fund and any remaining
net assets of the Company as a result of such liquidation with respect to his, her or its Insider Shares including any shares underlying
the Private Units (“Claim”) and hereby waives any Claim the undersigned may have in the future as a result
of, or arising out of, any contracts or agreements with the Company and will not seek recourse against the Trust Fund for any reason
whatsoever.  The undersigned acknowledges and agrees that there will be no distribution from the Trust Fund with respect
to any Rights underlying the Private Units, all of which will terminate on the Company’s liquidation.


 


3.     
    In the event of the liquidation of the Trust Fund, the undersigned agrees to indemnify and hold harmless the Company
against any and all loss, liability, claims, damage and expense whatsoever (including, but not limited to, any and all legal or
other expenses reasonably incurred in investigating, preparing or defending against any litigation, whether pending or threatened,
or any claim whatsoever) which the Company may become subject as a result of any claim by any target business or vendor or other
person who is owed money by the Company for services rendered or products sold or contracted for, but only to the extent necessary
to ensure that such loss, liability, claim, damage or expense does not reduce the amount of funds in the Trust Fund; provided
that such indemnity shall not apply if such target business, vendor or other person has executed an agreement waiving any claims
against the Trust Fund.


 


4.     
      In the event that the Company does not consummate a Business Combination and must liquidate and its
remaining net assets are insufficient to complete such liquidation, the undersigned agrees to advance such funds necessary to complete
such liquidation and agrees not to seek recourse for such expenses.


 






    7


     


    

 


5.     
     The undersigned will escrow all of his, her or its Insider Shares pursuant to the terms of a Stock Escrow Agreement,
which the Company will enter into with the undersigned and an escrow agent acceptable to the Company.  After the underwriter
exercises its over-allotment option in full, the remaining portion of the underwriter’s over-allotment option is canceled,
or the underwriter’s over-allotment option terminates, the undersigned agrees to cancel a portion of the undersigned’s
Insider Shares such that the total number of Insider Shares equals (i) .25 multiplied by (ii) the number of Units sold in the IPO.


 


6.     
      The undersigned agrees that until the Company consummates a Business Combination, the undersigned’s
Private Units will be subject to the transfer restrictions described in the Subscription Agreement relating to the undersigned’s
Private Units.


7.     
      In order to minimize potential conflicts of interest which may arise from multiple affiliations, the
undersigned agrees to present to the Company for its consideration, prior to presentation to any other person or entity, any suitable
opportunity to acquire a target business, until the earlier of the consummation by the Company of a Business Combination or the
liquidation of the Company, subject to any pre-existing fiduciary and contractual obligations the undersigned might have.


 


8.     
     The undersigned acknowledges and agrees that prior to entering into a Business Combination with a target business
that is affiliated with any Insiders of the Company or their affiliates, including any company that is a portfolio company of,
or otherwise affiliated with, or has received financial investment from, an entity with which any Insider or their affiliates is
affiliated, such transaction must be approved by a majority of the Company’s disinterested independent directors and the
Company must obtain an opinion from an independent investment banking firm that such Business Combination is fair to the Company’s
unaffiliated shareholders from a financial point of view.


 


9.     
      Neither the undersigned, any member of the family of the undersigned, nor any affiliate of the undersigned
will be entitled to receive and will not accept any compensation or other cash payment prior to, or for services rendered in connection
with, the consummation of the Business Combination; provided that the Company shall be allowed to repay working capital
loans made by the undersigned to the Company in cash upon consummation of the Business Combination.  Notwithstanding the
foregoing, the undersigned and any affiliate of the undersigned shall be entitled to reimbursement from the Company for their out-of-pocket
expenses incurred in connection with identifying, investigating and consummating a Business Combination.


 


10.     
      Neither the undersigned, any member of the family of the undersigned, nor any affiliate of the undersigned
will be entitled to receive or accept a finder’s fee or any other compensation in the event the undersigned, any member of
the family of the undersigned or any affiliate of the undersigned originates a Business Combination. 


 






    8


     


    

 


11.     
    The undersigned’s FINRA Questionnaire previously furnished to the Company and the Representative is true and
accurate in all material respects.  The undersigned represents and warrants that:


   


	 	(a)	He, she or it has never had a petition under the federal bankruptcy laws or any state insolvency law been filed by or against (i) him, her or it, or any partnership in which he or she was a general partner at or within two years before the time of filing; or (ii) any corporation or business association of which he or she was an executive officer at or within two years before the time of such filing;


 


	 	(b)	He, she or it has never had a receiver, fiscal agent or similar officer been appointed by a court for his business or property, or any such partnership;


 


	 	(c)	He, she or it has never been convicted of fraud in a civil or criminal proceeding;


 


	 	(d)	He, she or it has never been convicted in a criminal proceeding or named the subject of a pending criminal proceeding (excluding traffic violations and minor offenses);


 


	 	(e)	He, she or it has never been the subject of any order, judgment or decree, not subsequently reversed, suspended or vacated, of any court of competent jurisdiction, permanently or temporarily enjoining or otherwise limiting him, her or it from (i) acting as a futures commission merchant, introducing broker, commodity trading advisor, commodity pool operator, floor broker, leverage transaction merchant, any other person regulated by the Commodity Futures Trading Commission (“CFTC”) or an associated person of any of the foregoing, or as an investment adviser, underwriter, broker or dealer in securities, or as an affiliated person, director or employee of any investment company, bank, savings and loan association or insurance company, or from engaging in or continuing any conduct or practice in connection with any such activity; or (ii) engaging in any type of business practice; or (iii) engaging in any activity in connection with the purchase or sale of any security or commodity or in connection with any violation of federal or state securities or federal commodities laws;


 


	 	(f)	He, she, or it has never been the subject of any order, judgment or decree, not subsequently reversed, suspended or vacated, of any federal or state authority barring, suspending or otherwise limiting for more than 60 days his, her or its right to engage in any activity described in 11(e)(i) above, or to be associated with persons engaged in any such activity;


  


	 	(g)	He, she, or it has never been found by a court of competent jurisdiction in a civil action or by the SEC to have violated any federal or state securities law, where the judgment in such civil action or finding by the SEC has not been subsequently reversed, suspended or vacated;


 


	 	(h)	He, she, or it has never been found by a court of competent jurisdiction in a civil action or by the CFTC to have violated any federal commodities law, where the judgment in such civil action or finding by the CFTC has not been subsequently reversed, suspended or vacated;


 


	 	(i)	He, she, or it has never been the subject of, or a party to, any Federal, State or foreign judicial or administrative order, judgment, decree or finding, not subsequently reversed, suspended or vacated, relating to an alleged violation of (i) any Federal, State or foreign securities or commodities law or regulation, (ii) any law or regulation respecting financial institutions or insurance companies including, but not limited to, a temporary or permanent injunction, order of disgorgement or restitution, civil money penalty or temporary or permanent cease-and desist order, or removal or prohibition order or (iii) any law or regulation prohibiting mail or wire fraud or fraud in connection with any business entity;


 


	 	(j)	He, she or it has never been the subject of, or party to, any sanction or order, not subsequently reversed, suspended or vacated, or any self-regulatory organization, any registered entity, or any equivalent exchange, association, entity or organization that has disciplinary authority over its members or persons associated with a member;


 


	 	(k)	He, she or it has never been convicted of any felony or misdemeanor: (i) in connection with the purchase or sale of any security; (ii) involving the making of any false filing with the SEC; or (iii) arising out of the conduct of the business of an underwriter, broker, dealer, municipal securities dealer, investment advisor or paid solicitor of purchasers of securities;


 






    9


     


    

 


	 	(l)	He, she or it was never subject to a final order of a state or foreign  securities commission (or an agency of officer of a state performing like functions); a state or foreign authority that supervises or examines banks, savings associations, or credit unions; a state or foreign insurance commission (or an agency or officer of a state performing like functions); an appropriate federal or foreign banking agency; the CFTC; or the National Credit Union Administration that is based on a violation of any law or regulation that prohibits fraudulent, manipulative, or deceptive conduct;


 


	 	(m)	He, she or it has never been subject to any order, judgment or decree of any court of competent jurisdiction, that, at the time of the sale of the Units, restrained or enjoined him, her or it from engaging or continuing to engage in any conduct or practice: (i) in connection with the purchase or sale of any security; (ii) involving the making of any false filing with the SEC or any foreign regulatory agency with similar functions; or (iii) arising out of the conduct of the business of an underwriter, broker, dealer, municipal securities dealer, investment adviser or paid solicitor of purchasers of securities;


 


	 	(n)	He, she or it has never been subject to any order of the SEC or any foreign regulatory agency with similar functions that orders him, her or it to cease and desist from committing or causing a future violation of: (i) any scienter-based anti-fraud provision of the federal securities laws, including, but not limited to, Section 17(a)(1) of the Securities Act, Section 10(b) of the Exchange Act and Rule 10b-5 thereunder, Section 15(c) and Section 206(1) of the Advisers Act or any other rule or regulation thereunder; or (ii) Section 5 of the Securities Act;


 


	 	(o)	He, she or it has never filed (as a registrant or issuer), or been named as an underwriter in any registration statement or Regulation A offering statement filed with the SEC that was the subject of a refusal order, stop order, or order suspending the Regulation A exemption, or is, currently, the subject of an investigation or proceeding to determine whether a stop order or suspension order should be issued;


 


	 	(p)	He, she or it has never been subject to a United States Postal Service false representation order, or is currently subject to a temporary restraining order or preliminary injunction with respect to conduct alleged by the United States Postal Service to constitute a scheme or device for obtaining money or property through the mail by means of false representations;


 


	 	(q)	He, she or it is not subject to a final order of a state securities commission (or an agency of officer of a state performing like functions); a state authority that supervises or examines banks, savings associations, or credit unions; a state insurance commission (or an agency or officer of a state performing like functions); an appropriate federal banking agency; the CFTC; or the National Credit Union Administration that bars the undersigned from: (i) association with an entity regulated by such commission, authority, agency or officer; (ii) engaging in the business of securities, insurance or banking; or (iii) engaging in savings association or credit union activities;


 


	 	(r)	He, she or it is not subject to an order of the SEC entered pursuant to section 15(b) or 15B(c) of the Securities Exchange Act of 1934 (the “Exchange Act”) or section 203(e) or 203(f) of the Investment Advisers Act of 1940 (the “Advisers Act”) that: (i) suspends or revokes the undersigned’s registration as a broker, dealer, municipal securities dealer or investment adviser; (ii) places limitations on the activities, functions or operations of, or imposes civil money penalties on, such person; or (iii) bars the undersigned from being associated with any entity or from participating in the offering of any penny stock; and


 


	 	(s)	He, she or it has never been suspended or expelled from membership in, or suspended or barred from association with a member of, a securities self-regulatory organization (e.g., a registered national securities exchange or a registered national or affiliated securities association) for any act or omission to act constituting conduct inconsistent with just and equitable principles of trade.


 


12.     
The undersigned has full right and power, without violating any agreement by which he, she or it is bound, to enter into this letter
agreement.


 


13.      
The undersigned hereby waives his, her or its right to exercise redemption rights with respect to any shares of Common Stock owned
or to be owned by the undersigned, directly or indirectly, whether purchased by the undersigned prior to the IPO, in the IPO or
in the aftermarket, and agrees that he, she or it will not seek redemption with respect to or otherwise sell, such shares in connection
with any vote to approve a Business Combination with respect thereto, a vote to amend the provisions of the Company’s Amended
and Restated Certificate of Incorporation, or a tender offer by the Company prior to a Business Combination.


 


14.     
The undersigned hereby agrees to not propose, or vote in favor of, an amendment to the Company’s Amended and Restated Certificate
of Incorporation with respect to the Company’s pre-Business Combination activities prior to the consummation of a Business
Combination unless the Company offers holders of IPO Shares the right to receive their pro rata portion of the funds then held
in the Trust Fund.


 






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15.       
In connection with Section 5-1401 of the General Obligations Law of the State of New York, this letter agreement shall be governed
by, and construed in accordance with, the laws of the State of New York without regard to principles of conflicts of law that would
result in the application of the substantive law of another jurisdiction.  The parties hereto agree that any action, proceeding
or claim arising out of or relating in any way to this letter agreement shall be resolved through final and binding arbitration
in accordance with the International Arbitration Rules of the American Arbitration Association (“AAA”).  The
arbitration shall be brought before the AAA International Center for Dispute Resolution’s offices in New York City, New York,
will be conducted in English and will be decided by a panel of three arbitrators selected from the AAA Commercial Disputes Panel
and that the arbitrator panel’s decision shall be final and enforceable by any court having jurisdiction over the party from
whom enforcement is sought.  The cost of such arbitrators and arbitration services, together with the prevailing party’s
legal fees and expenses, shall be borne by the non-prevailing party or as otherwise directed by the arbitrators. 


  


16.      
As used herein, (i) a “Business Combination” shall mean a merger, share exchange, asset acquisition,
contractual arrangement, share purchase, recapitalization, reorganization or other similar business combination with one or more
businesses or entities; (ii) “Insiders” shall mean all officers, directors and shareholders of the Company
immediately prior to the IPO; (iii) “Insider Shares” shall mean all of the shares of Common Stock of
the Company acquired by an Insider prior to the IPO and any shares of Common Stock underlying the Private Units; (iv) “IPO
Shares” shall mean the shares of Common Stock issued in the Company’s IPO; (v) “Private Units”
shall mean (x) the Units purchased in the private placement taking place simultaneously with the consummation of the Company’s
IPO and (y) the additional Units that may be purchased in connection with the exercise of the over-allotment option by the underwriters
in the IPO as described in the Registration Statement; (vi) “Registration Statement” means the registration
statement on Form S-1 filed by the Company with respect to the IPO; and (vii) “Trust Fund” shall mean
the trust fund into which a portion of the net proceeds of the Company’s IPO will be deposited.


 


17.      
Any notice, consent or request to be given in connection with any of the terms or provisions of this letter agreement shall be
in writing and shall be sent by express mail or similar private courier service, by certified mail (return receipt requested),
by hand delivery or facsimile transmission.


 


If to the Representative:


 


Chardan Capital Markets, LLC


17 State Street, Suite 1600


New York, NY 10004


Attn: George Kaufman


Facsimile: (646) 465-9039


 


with a copy (which copy shall not constitute
notice) to:


 


Scarinci Hollenbeck, LLC


3 Park Avenue, 15th Floor


New York, NY 10016


Attn: Dan Brecher


Fax No.: (212) 808-4155


  


If to the Company:


 


Mountain Crest Acquisition Corp


311 West 43rd Street, 12 Floor


New York, NY 10036


Attn:  Suying Liu,  Chief
Executive Officer


 


with a copy (which copy shall not constitute
notice) to:


 


Loeb & Loeb LLP


345 Park Avenue


New York, NY 10154


Attn: Giovanni Caruso, Esq.


Facsimile: (212) 504-3013


 






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18.      
No party hereto may assign either this letter agreement or any of its rights, interests, or obligations hereunder without the prior
written consent of the other party. Any purported assignment in violation of this paragraph shall be void and ineffectual and shall
not operate to transfer or assign any interest or title to the purported assignee. This letter agreement shall be binding on the
parties hereto and any successors and assigns thereof.


 


19.      
The undersigned acknowledges and understands that the Underwriters and the Company will rely upon the agreements, representations
and warranties set forth herein in proceeding with the IPO.


 


[Signature Page Follows]


 






    12


     


    

  


	 	Sincerely,
	 	 	 
	 	SUNLIGHT GLOBAL INVESTMENT LLC
	 	 
	 	By:	 /s/ Suying Liu
	 	 	Name: Suying Liu
	 	 	Title:    Member



  


[SIGNATURE PAGE TO LETTER AGREEMENT]


  











    13


     


    

  


June 4, 2020


 


Mountain Crest Acquisition Corp


311 West 43rd Street, 12th Floor


New York, NY 10036


 


Chardan Capital Markets,
LLC


17 State Street, Suite 1600


New York, NY 10004


 


           
             Re:       Initial
Public Offering


 


Gentlemen:


 


This letter is being
delivered to you in accordance with the Underwriting Agreement (the “Underwriting Agreement”) entered
into by and between Mountain Crest Acquisition Corp, a Delaware corporation (the “Company”), and Chardan
Capital Markets, LLC, as Representative (the “Representative”) of the several underwriters named on Schedule
A thereto (the “Underwriters”), relating to an underwritten initial public offering (the “IPO”)
of the Company’s units (the “Units”), each comprised of one share of common stock of the Company,
$.0001 par value (the “Common Stock”) and one right to receive one-tenth (1/10) of one share of Common
Stock (the “Rights”). Certain capitalized terms used herein are defined in paragraph 16 hereof.


 


In order to induce the
Company and the Underwriters to enter into the Underwriting Agreement and to proceed with the IPO, and in recognition of the benefit
that such IPO will confer upon the undersigned as a shareholder of the Company, and for other good and valuable consideration,
the receipt and sufficiency of which are hereby acknowledged, the undersigned hereby agrees with the Company as follows:


 


1.     
      If the Company solicits approval of its shareholders of a Business Combination, the undersigned will
vote all shares of Common Stock beneficially owned by him, her or it, whether acquired before, in or after the IPO, in favor of
such Business Combination.


 


2.      
     (a)  Unless the Company’s shareholders are previously given the option to redeem their shares
in connection with amending applicable documents to extend the time that the Company has to complete a Business Combination and
the Company fails to consummate a Business Combination within 12 months from the closing of the Company’s IPO (or, in the
event that the Company extended the period of time to consummate a business combination up to three times, each by an additional
three months, up to 21 months from the closing of the Company’s IPO), the undersigned shall take all reasonable steps to
(i) cause the Trust Fund to be liquidated and distributed to the holders of the IPO Shares and (ii) cause the Company to liquidate
as soon as reasonably practicable.


  


(b) The undersigned
hereby waives any and all right, title, interest or claim of any kind in or to any distribution of the Trust Fund and any remaining
net assets of the Company as a result of such liquidation with respect to his, her or its Insider Shares including any shares underlying
the Private Units (“Claim”) and hereby waives any Claim the undersigned may have in the future as a result
of, or arising out of, any contracts or agreements with the Company and will not seek recourse against the Trust Fund for any reason
whatsoever.  The undersigned acknowledges and agrees that there will be no distribution from the Trust Fund with respect
to any Rights underlying the Private Units, all of which will terminate on the Company’s liquidation.


 


3.     
    Intentionally Omitted


 


4.     
    Intentionally Omitted


 


5.     
     The undersigned will escrow all of his, her or its Insider Shares pursuant to the terms of a Stock Escrow Agreement,
which the Company will enter into with the undersigned and an escrow agent acceptable to the Company.  After the underwriter
exercises its over-allotment option in full, the remaining portion of the underwriter’s over-allotment option is canceled,
or the underwriter’s over-allotment option terminates, the undersigned agrees to cancel a portion of the undersigned’s
Insider Shares such that the total number of Insider Shares equals (i) .25 multiplied by (ii) the number of Units sold in the IPO.


 


6.     
      The undersigned agrees that until the Company consummates a Business Combination, the undersigned’s
Private Units will be subject to the transfer restrictions described in the Subscription Agreement relating to the undersigned’s
Private Units.


 






    1


     


    

 


7.     
      In order to minimize potential conflicts of interest which may arise from multiple affiliations, the
undersigned agrees to present to the Company for its consideration, prior to presentation to any other person or entity, any suitable
opportunity to acquire a target business, until the earlier of the consummation by the Company of a Business Combination or the
liquidation of the Company, subject to any pre-existing fiduciary and contractual obligations the undersigned might have.


 


8.     
     The undersigned acknowledges and agrees that prior to entering into a Business Combination with a target business
that is affiliated with any Insiders of the Company or their affiliates, including any company that is a portfolio company of,
or otherwise affiliated with, or has received financial investment from, an entity with which any Insider or their affiliates is
affiliated, such transaction must be approved by a majority of the Company’s disinterested independent directors and the
Company must obtain an opinion from an independent investment banking firm that such Business Combination is fair to the Company’s
unaffiliated shareholders from a financial point of view.


 


9.     
      Neither the undersigned, any member of the family of the undersigned, nor any affiliate of the undersigned
will be entitled to receive and will not accept any compensation or other cash payment prior to, or for services rendered in connection
with, the consummation of the Business Combination; provided that the Company shall be allowed to repay working capital
loans made by the undersigned to the Company in cash upon consummation of the Business Combination.  Notwithstanding the
foregoing, the undersigned and any affiliate of the undersigned shall be entitled to reimbursement from the Company for their out-of-pocket
expenses incurred in connection with identifying, investigating and consummating a Business Combination.


 


10.     
      Neither the undersigned, any member of the family of the undersigned, nor any affiliate of the undersigned
will be entitled to receive or accept a finder’s fee or any other compensation in the event the undersigned, any member of
the family of the undersigned or any affiliate of the undersigned originates a Business Combination. 


 


11.     
    The undersigned agrees to be a director of the Company until the earlier of the consummation by the Company of a
Business Combination or the liquidation of the Company.  The undersigned’s biographical information previously furnished
to the Company and the Representative is true and accurate in all material respects, does not omit any material information with
respect to the undersigned’s biography and contains all of the information required to be disclosed pursuant to Item 401
of Regulation S-K, promulgated under the Securities Act of 1933.  The undersigned’s FINRA Questionnaire previously
furnished to the Company and the Representative is true and accurate in all material respects.  The undersigned represents
and warrants that:


 


	 	(a)	He, she or it has never had a petition under the federal bankruptcy laws or any state insolvency law been filed by or against (i) him, her or it, or any partnership in which he or she was a general partner at or within two years before the time of filing; or (ii) any corporation or business association of which he or she was an executive officer at or within two years before the time of such filing;


 


	 	(b)	He, she or it has never had a receiver, fiscal agent or similar officer been appointed by a court for his business or property, or any such partnership;


 


	 	(c)	He, she or it has never been convicted of fraud in a civil or criminal proceeding;


 


	 	(d)	He, she or it has never been convicted in a criminal proceeding or named the subject of a pending criminal proceeding (excluding traffic violations and minor offenses);


 


	 	(e)	He, she or it has never been the subject of any order, judgment or decree, not subsequently reversed, suspended or vacated, of any court of competent jurisdiction, permanently or temporarily enjoining or otherwise limiting him, her or it from (i) acting as a futures commission merchant, introducing broker, commodity trading advisor, commodity pool operator, floor broker, leverage transaction merchant, any other person regulated by the Commodity Futures Trading Commission (“CFTC”) or an associated person of any of the foregoing, or as an investment adviser, underwriter, broker or dealer in securities, or as an affiliated person, director or employee of any investment company, bank, savings and loan association or insurance company, or from engaging in or continuing any conduct or practice in connection with any such activity; or (ii) engaging in any type of business practice; or (iii) engaging in any activity in connection with the purchase or sale of any security or commodity or in connection with any violation of federal or state securities or federal commodities laws;


 


	 	(f)	He, she, or it has never been the subject of any order, judgment or decree, not subsequently reversed, suspended or vacated, of any federal or state authority barring, suspending or otherwise limiting for more than 60 days his, her or its right to engage in any activity described in 11(e)(i) above, or to be associated with persons engaged in any such activity;


  



    2


     


    

 


	 	(g)	He, she, or it has never been found by a court of competent jurisdiction in a civil action or by the SEC to have violated any federal or state securities law, where the judgment in such civil action or finding by the SEC has not been subsequently reversed, suspended or vacated;


 


	 	(h)	He, she, or it has never been found by a court of competent jurisdiction in a civil action or by the CFTC to have violated any federal commodities law, where the judgment in such civil action or finding by the CFTC has not been subsequently reversed, suspended or vacated;


 


	 	(i)	He, she, or it has never been the subject of, or a party to, any Federal, State or foreign judicial or administrative order, judgment, decree or finding, not subsequently reversed, suspended or vacated, relating to an alleged violation of (i) any Federal, State or foreign securities or commodities law or regulation, (ii) any law or regulation respecting financial institutions or insurance companies including, but not limited to, a temporary or permanent injunction, order of disgorgement or restitution, civil money penalty or temporary or permanent cease-and desist order, or removal or prohibition order or (iii) any law or regulation prohibiting mail or wire fraud or fraud in connection with any business entity;


 


	 	(j)	He, she or it has never been the subject of, or party to, any sanction or order, not subsequently reversed, suspended or vacated, or any self-regulatory organization, any registered entity, or any equivalent exchange, association, entity or organization that has disciplinary authority over its members or persons associated with a member;


 


	 	(k)	He, she or it has never been convicted of any felony or misdemeanor: (i) in connection with the purchase or sale of any security; (ii) involving the making of any false filing with the SEC; or (iii) arising out of the conduct of the business of an underwriter, broker, dealer, municipal securities dealer, investment advisor or paid solicitor of purchasers of securities;


 


	 	(l)	He, she or it was never subject to a final order of a state or foreign  securities commission (or an agency of officer of a state performing like functions); a state or foreign authority that supervises or examines banks, savings associations, or credit unions; a state or foreign insurance commission (or an agency or officer of a state performing like functions); an appropriate federal or foreign banking agency; the CFTC; or the National Credit Union Administration that is based on a violation of any law or regulation that prohibits fraudulent, manipulative, or deceptive conduct;


  


	 	(m)	He, she or it has never been subject to any order, judgment or decree of any court of competent jurisdiction, that, at the time of the sale of the Units, restrained or enjoined him, her or it from engaging or continuing to engage in any conduct or practice: (i) in connection with the purchase or sale of any security; (ii) involving the making of any false filing with the SEC or any foreign regulatory agency with similar functions; or (iii) arising out of the conduct of the business of an underwriter, broker, dealer, municipal securities dealer, investment adviser or paid solicitor of purchasers of securities;


 


	 	(n)	He, she or it has never been subject to any order of the SEC or any foreign regulatory agency with similar functions that orders him, her or it to cease and desist from committing or causing a future violation of: (i) any scienter-based anti-fraud provision of the federal securities laws, including, but not limited to, Section 17(a)(1) of the Securities Act, Section 10(b) of the Exchange Act and Rule 10b-5 thereunder, Section 15(c) and Section 206(1) of the Advisers Act or any other rule or regulation thereunder; or (ii) Section 5 of the Securities Act;


 


	 	(o)	He, she or it has never filed (as a registrant or issuer), or been named as an underwriter in any registration statement or Regulation A offering statement filed with the SEC that was the subject of a refusal order, stop order, or order suspending the Regulation A exemption, or is, currently, the subject of an investigation or proceeding to determine whether a stop order or suspension order should be issued;


 


	 	(p)	He, she or it has never been subject to a United States Postal Service false representation order, or is currently subject to a temporary restraining order or preliminary injunction with respect to conduct alleged by the United States Postal Service to constitute a scheme or device for obtaining money or property through the mail by means of false representations;


 






    3


     


    

 


	 	(q)	He, she or it is not subject to a final order of a state securities commission (or an agency of officer of a state performing like functions); a state authority that supervises or examines banks, savings associations, or credit unions; a state insurance commission (or an agency or officer of a state performing like functions); an appropriate federal banking agency; the CFTC; or the National Credit Union Administration that bars the undersigned from: (i) association with an entity regulated by such commission, authority, agency or officer; (ii) engaging in the business of securities, insurance or banking; or (iii) engaging in savings association or credit union activities;


  


	 	(r)	He, she or it is not subject to an order of the SEC entered pursuant to section 15(b) or 15B(c) of the Securities Exchange Act of 1934 (the “Exchange Act”) or section 203(e) or 203(f) of the Investment Advisers Act of 1940 (the “Advisers Act”) that: (i) suspends or revokes the undersigned’s registration as a broker, dealer, municipal securities dealer or investment adviser; (ii) places limitations on the activities, functions or operations of, or imposes civil money penalties on, such person; or (iii) bars the undersigned from being associated with any entity or from participating in the offering of any penny stock; and


 


	 	(s)	He, she or it has never been suspended or expelled from membership in, or suspended or barred from association with a member of, a securities self-regulatory organization (e.g., a registered national securities exchange or a registered national or affiliated securities association) for any act or omission to act constituting conduct inconsistent with just and equitable principles of trade.


 


12.     
The undersigned has full right and power, without violating any agreement by which he, she or it is bound, to enter into this letter
agreement and to serve as a Director and/or officer of the Company.


 


13.      
The undersigned hereby waives his, her or its right to exercise redemption rights with respect to any shares of Common Stock owned
or to be owned by the undersigned, directly or indirectly, whether purchased by the undersigned prior to the IPO, in the IPO or
in the aftermarket, and agrees that he, she or it will not seek redemption with respect to or otherwise sell, such shares in connection
with any vote to approve a Business Combination with respect thereto, a vote to amend the provisions of the Company’s Amended
and Restated Certificate of Incorporation, or a tender offer by the Company prior to a Business Combination.


 


14.     
The undersigned hereby agrees to not propose, or vote in favor of, an amendment to the Company’s Amended and Restated Certificate
of Incorporation with respect to the Company’s pre-Business Combination activities prior to the consummation of a Business
Combination unless the Company offers holders of IPO Shares the right to receive their pro rata portion of the funds then held
in the Trust Fund.


 


15.       
In connection with Section 5-1401 of the General Obligations Law of the State of New York, this letter agreement shall be governed
by, and construed in accordance with, the laws of the State of New York without regard to principles of conflicts of law that would
result in the application of the substantive law of another jurisdiction.  The parties hereto agree that any action, proceeding
or claim arising out of or relating in any way to this letter agreement shall be resolved through final and binding arbitration
in accordance with the International Arbitration Rules of the American Arbitration Association (“AAA”).  The
arbitration shall be brought before the AAA International Center for Dispute Resolution’s offices in New York City, New York,
will be conducted in English and will be decided by a panel of three arbitrators selected from the AAA Commercial Disputes Panel
and that the arbitrator panel’s decision shall be final and enforceable by any court having jurisdiction over the party from
whom enforcement is sought.  The cost of such arbitrators and arbitration services, together with the prevailing party’s
legal fees and expenses, shall be borne by the non-prevailing party or as otherwise directed by the arbitrators. 


  


16.      
As used herein, (i) a “Business Combination” shall mean a merger, share exchange, asset acquisition,
contractual arrangement, share purchase, recapitalization, reorganization or other similar business combination with one or more
businesses or entities; (ii) “Insiders” shall mean all officers, directors and shareholders of the Company
immediately prior to the IPO; (iii) “Insider Shares” shall mean all of the shares of Common Stock of
the Company acquired by an Insider prior to the IPO and any shares of Common Stock underlying the Private Units; (iv) “IPO
Shares” shall mean the shares of Common Stock issued in the Company’s IPO; (v) “Private Units”
shall mean (x) the Units purchased in the private placement taking place simultaneously with the consummation of the Company’s
IPO and (y) the additional Units that may be purchased in connection with the exercise of the over-allotment option by the underwriters
in the IPO as described in the Registration Statement; (vi) “Registration Statement” means the registration
statement on Form S-1 filed by the Company with respect to the IPO; and (vii) “Trust Fund” shall mean
the trust fund into which a portion of the net proceeds of the Company’s IPO will be deposited.


 


17.      
Any notice, consent or request to be given in connection with any of the terms or provisions of this letter agreement shall be
in writing and shall be sent by express mail or similar private courier service, by certified mail (return receipt requested),
by hand delivery or facsimile transmission.


 






    4


     


    

 


If to the Representative:


 


Chardan Capital Markets, LLC


17 State Street, Suite 1600


New York, NY 10004


Attn: George Kaufman


Facsimile: (646) 465-9039


 


with a copy (which copy shall not constitute
notice) to:


 


Scarinci Hollenbeck, LLC


3 Park Avenue, 15th Floor


New York, NY 10016


Attn: Dan Brecher


Fax No.: (212) 808-4155


 


If to the Company:


 


Mountain Crest Acquisition Corp


311 West 43rd Street, 12 Floor


New York, NY 10036


Attn:  Suying Liu,  Chief
Executive Officer


 


with a copy (which copy shall not constitute
notice) to:


 


Loeb & Loeb LLP


345 Park Avenue


New York, NY 10154


Attn: Giovanni Caruso, Esq.


Facsimile: (212) 504-3013


 


18.      
No party hereto may assign either this letter agreement or any of its rights, interests, or obligations hereunder without the prior
written consent of the other party. Any purported assignment in violation of this paragraph shall be void and ineffectual and shall
not operate to transfer or assign any interest or title to the purported assignee. This letter agreement shall be binding on the
parties hereto and any successors and assigns thereof.


 


19.      
The undersigned acknowledges and understands that the Underwriters and the Company will rely upon the agreements, representations
and warranties set forth herein in proceeding with the IPO.


 


[Signature Page Follows]


  


 



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	 	Sincerely,
	 	 
	 	By:	 /s/ Todd Milbourn
	 	 	Name of Insider: Todd Milbourn


  


[SIGNATURE PAGE TO LETTER AGREEMENT]


  








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June 4, 2020


 


Mountain Crest Acquisition Corp


311 West 43rd Street, 12th Floor


New York, NY 10036


 


Chardan Capital Markets,
LLC


17 State Street, Suite 1600


New York, NY 10004


 


           
             Re:       Initial
Public Offering


 


Gentlemen:


 


This letter is being
delivered to you in accordance with the Underwriting Agreement (the “Underwriting Agreement”) entered
into by and between Mountain Crest Acquisition Corp, a Delaware corporation (the “Company”), and Chardan
Capital Markets, LLC, as Representative (the “Representative”) of the several underwriters named on Schedule
A thereto (the “Underwriters”), relating to an underwritten initial public offering (the “IPO”)
of the Company’s units (the “Units”), each comprised of one share of common stock of the Company,
$.0001 par value (the “Common Stock”) and one right to receive one-tenth (1/10) of one share of Common
Stock (the “Rights”). Certain capitalized terms used herein are defined in paragraph 16 hereof.


 


In order to induce the
Company and the Underwriters to enter into the Underwriting Agreement and to proceed with the IPO, and in recognition of the benefit
that such IPO will confer upon the undersigned as a shareholder of the Company, and for other good and valuable consideration,
the receipt and sufficiency of which are hereby acknowledged, the undersigned hereby agrees with the Company as follows:


 


1.     
      If the Company solicits approval of its shareholders of a Business Combination, the undersigned will
vote all shares of Common Stock beneficially owned by him, her or it, whether acquired before, in or after the IPO, in favor of
such Business Combination.


 


2.      
     (a)  Unless the Company’s shareholders are previously given the option to redeem their shares
in connection with amending applicable documents to extend the time that the Company has to complete a Business Combination and
the Company fails to consummate a Business Combination within 12 months from the closing of the Company’s IPO (or, in the
event that the Company extended the period of time to consummate a business combination up to three times, each by an additional
three months, up to 21 months from the closing of the Company’s IPO), the undersigned shall take all reasonable steps to
(i) cause the Trust Fund to be liquidated and distributed to the holders of the IPO Shares and (ii) cause the Company to liquidate
as soon as reasonably practicable.


  


(b) The undersigned
hereby waives any and all right, title, interest or claim of any kind in or to any distribution of the Trust Fund and any remaining
net assets of the Company as a result of such liquidation with respect to his, her or its Insider Shares including any shares underlying
the Private Units (“Claim”) and hereby waives any Claim the undersigned may have in the future as a result
of, or arising out of, any contracts or agreements with the Company and will not seek recourse against the Trust Fund for any reason
whatsoever.  The undersigned acknowledges and agrees that there will be no distribution from the Trust Fund with respect
to any Rights underlying the Private Units, all of which will terminate on the Company’s liquidation.


 


3.     
    Intentionally Omitted


 


4.     
    Intentionally Omitted


 


5.     
     The undersigned will escrow all of his, her or its Insider Shares pursuant to the terms of a Stock Escrow Agreement,
which the Company will enter into with the undersigned and an escrow agent acceptable to the Company.  After the underwriter
exercises its over-allotment option in full, the remaining portion of the underwriter’s over-allotment option is canceled,
or the underwriter’s over-allotment option terminates, the undersigned agrees to cancel a portion of the undersigned’s
Insider Shares such that the total number of Insider Shares equals (i) .25 multiplied by (ii) the number of Units sold in the IPO.


 


6.     
      The undersigned agrees that until the Company consummates a Business Combination, the undersigned’s
Private Units will be subject to the transfer restrictions described in the Subscription Agreement relating to the undersigned’s
Private Units.


 






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7.     
      In order to minimize potential conflicts of interest which may arise from multiple affiliations, the
undersigned agrees to present to the Company for its consideration, prior to presentation to any other person or entity, any suitable
opportunity to acquire a target business, until the earlier of the consummation by the Company of a Business Combination or the
liquidation of the Company, subject to any pre-existing fiduciary and contractual obligations the undersigned might have.


 


8.     
     The undersigned acknowledges and agrees that prior to entering into a Business Combination with a target business
that is affiliated with any Insiders of the Company or their affiliates, including any company that is a portfolio company of,
or otherwise affiliated with, or has received financial investment from, an entity with which any Insider or their affiliates is
affiliated, such transaction must be approved by a majority of the Company’s disinterested independent directors and the
Company must obtain an opinion from an independent investment banking firm that such Business Combination is fair to the Company’s
unaffiliated shareholders from a financial point of view.


 


9.     
      Neither the undersigned, any member of the family of the undersigned, nor any affiliate of the undersigned
will be entitled to receive and will not accept any compensation or other cash payment prior to, or for services rendered in connection
with, the consummation of the Business Combination; provided that the Company shall be allowed to repay working capital
loans made by the undersigned to the Company in cash upon consummation of the Business Combination.  Notwithstanding the
foregoing, the undersigned and any affiliate of the undersigned shall be entitled to reimbursement from the Company for their out-of-pocket
expenses incurred in connection with identifying, investigating and consummating a Business Combination.


 


10.     
      Neither the undersigned, any member of the family of the undersigned, nor any affiliate of the undersigned
will be entitled to receive or accept a finder’s fee or any other compensation in the event the undersigned, any member of
the family of the undersigned or any affiliate of the undersigned originates a Business Combination. 


 


11.     
    The undersigned agrees to be a director of the Company until the earlier of the consummation by the Company of a
Business Combination or the liquidation of the Company.  The undersigned’s biographical information previously furnished
to the Company and the Representative is true and accurate in all material respects, does not omit any material information with
respect to the undersigned’s biography and contains all of the information required to be disclosed pursuant to Item 401
of Regulation S-K, promulgated under the Securities Act of 1933.  The undersigned’s FINRA Questionnaire previously
furnished to the Company and the Representative is true and accurate in all material respects.  The undersigned represents
and warrants that:


 


	 	(a)	He, she or it has never had a petition under the federal bankruptcy laws or any state insolvency law been filed by or against (i) him, her or it, or any partnership in which he or she was a general partner at or within two years before the time of filing; or (ii) any corporation or business association of which he or she was an executive officer at or within two years before the time of such filing;


 


	 	(b)	He, she or it has never had a receiver, fiscal agent or similar officer been appointed by a court for his business or property, or any such partnership;


 


	 	(c)	He, she or it has never been convicted of fraud in a civil or criminal proceeding;


 


	 	(d)	He, she or it has never been convicted in a criminal proceeding or named the subject of a pending criminal proceeding (excluding traffic violations and minor offenses);


 


	 	(e)	He, she or it has never been the subject of any order, judgment or decree, not subsequently reversed, suspended or vacated, of any court of competent jurisdiction, permanently or temporarily enjoining or otherwise limiting him, her or it from (i) acting as a futures commission merchant, introducing broker, commodity trading advisor, commodity pool operator, floor broker, leverage transaction merchant, any other person regulated by the Commodity Futures Trading Commission (“CFTC”) or an associated person of any of the foregoing, or as an investment adviser, underwriter, broker or dealer in securities, or as an affiliated person, director or employee of any investment company, bank, savings and loan association or insurance company, or from engaging in or continuing any conduct or practice in connection with any such activity; or (ii) engaging in any type of business practice; or (iii) engaging in any activity in connection with the purchase or sale of any security or commodity or in connection with any violation of federal or state securities or federal commodities laws;


 


	 	(f)	He, she, or it has never been the subject of any order, judgment or decree, not subsequently reversed, suspended or vacated, of any federal or state authority barring, suspending or otherwise limiting for more than 60 days his, her or its right to engage in any activity described in 11(e)(i) above, or to be associated with persons engaged in any such activity;


 


 



    2


     


    

 


	 	(g)	He, she, or it has never been found by a court of competent jurisdiction in a civil action or by the SEC to have violated any federal or state securities law, where the judgment in such civil action or finding by the SEC has not been subsequently reversed, suspended or vacated;


 


	 	(h)	He, she, or it has never been found by a court of competent jurisdiction in a civil action or by the CFTC to have violated any federal commodities law, where the judgment in such civil action or finding by the CFTC has not been subsequently reversed, suspended or vacated;


 


	 	(i)	He, she, or it has never been the subject of, or a party to, any Federal, State or foreign judicial or administrative order, judgment, decree or finding, not subsequently reversed, suspended or vacated, relating to an alleged violation of (i) any Federal, State or foreign securities or commodities law or regulation, (ii) any law or regulation respecting financial institutions or insurance companies including, but not limited to, a temporary or permanent injunction, order of disgorgement or restitution, civil money penalty or temporary or permanent cease-and desist order, or removal or prohibition order or (iii) any law or regulation prohibiting mail or wire fraud or fraud in connection with any business entity;


 


	 	(j)	He, she or it has never been the subject of, or party to, any sanction or order, not subsequently reversed, suspended or vacated, or any self-regulatory organization, any registered entity, or any equivalent exchange, association, entity or organization that has disciplinary authority over its members or persons associated with a member;


 


	 	(k)	He, she or it has never been convicted of any felony or misdemeanor: (i) in connection with the purchase or sale of any security; (ii) involving the making of any false filing with the SEC; or (iii) arising out of the conduct of the business of an underwriter, broker, dealer, municipal securities dealer, investment advisor or paid solicitor of purchasers of securities;


 


	 	(l)	He, she or it was never subject to a final order of a state or foreign  securities commission (or an agency of officer of a state performing like functions); a state or foreign authority that supervises or examines banks, savings associations, or credit unions; a state or foreign insurance commission (or an agency or officer of a state performing like functions); an appropriate federal or foreign banking agency; the CFTC; or the National Credit Union Administration that is based on a violation of any law or regulation that prohibits fraudulent, manipulative, or deceptive conduct;


  


	 	(m)	He, she or it has never been subject to any order, judgment or decree of any court of competent jurisdiction, that, at the time of the sale of the Units, restrained or enjoined him, her or it from engaging or continuing to engage in any conduct or practice: (i) in connection with the purchase or sale of any security; (ii) involving the making of any false filing with the SEC or any foreign regulatory agency with similar functions; or (iii) arising out of the conduct of the business of an underwriter, broker, dealer, municipal securities dealer, investment adviser or paid solicitor of purchasers of securities;


 


	 	(n)	He, she or it has never been subject to any order of the SEC or any foreign regulatory agency with similar functions that orders him, her or it to cease and desist from committing or causing a future violation of: (i) any scienter-based anti-fraud provision of the federal securities laws, including, but not limited to, Section 17(a)(1) of the Securities Act, Section 10(b) of the Exchange Act and Rule 10b-5 thereunder, Section 15(c) and Section 206(1) of the Advisers Act or any other rule or regulation thereunder; or (ii) Section 5 of the Securities Act;


 


	 	(o)	He, she or it has never filed (as a registrant or issuer), or been named as an underwriter in any registration statement or Regulation A offering statement filed with the SEC that was the subject of a refusal order, stop order, or order suspending the Regulation A exemption, or is, currently, the subject of an investigation or proceeding to determine whether a stop order or suspension order should be issued;


 


	 	(p)	He, she or it has never been subject to a United States Postal Service false representation order, or is currently subject to a temporary restraining order or preliminary injunction with respect to conduct alleged by the United States Postal Service to constitute a scheme or device for obtaining money or property through the mail by means of false representations;


 






    3


     


    

 


	 	(q)	He, she or it is not subject to a final order of a state securities commission (or an agency of officer of a state performing like functions); a state authority that supervises or examines banks, savings associations, or credit unions; a state insurance commission (or an agency or officer of a state performing like functions); an appropriate federal banking agency; the CFTC; or the National Credit Union Administration that bars the undersigned from: (i) association with an entity regulated by such commission, authority, agency or officer; (ii) engaging in the business of securities, insurance or banking; or (iii) engaging in savings association or credit union activities;


  


	 	(r)	He, she or it is not subject to an order of the SEC entered pursuant to section 15(b) or 15B(c) of the Securities Exchange Act of 1934 (the “Exchange Act”) or section 203(e) or 203(f) of the Investment Advisers Act of 1940 (the “Advisers Act”) that: (i) suspends or revokes the undersigned’s registration as a broker, dealer, municipal securities dealer or investment adviser; (ii) places limitations on the activities, functions or operations of, or imposes civil money penalties on, such person; or (iii) bars the undersigned from being associated with any entity or from participating in the offering of any penny stock; and


 


	 	(s)	He, she or it has never been suspended or expelled from membership in, or suspended or barred from association with a member of, a securities self-regulatory organization (e.g., a registered national securities exchange or a registered national or affiliated securities association) for any act or omission to act constituting conduct inconsistent with just and equitable principles of trade.


 


12.     
The undersigned has full right and power, without violating any agreement by which he, she or it is bound, to enter into this letter
agreement and to serve as a Director and/or officer of the Company.


 


13.      
The undersigned hereby waives his, her or its right to exercise redemption rights with respect to any shares of Common Stock owned
or to be owned by the undersigned, directly or indirectly, whether purchased by the undersigned prior to the IPO, in the IPO or
in the aftermarket, and agrees that he, she or it will not seek redemption with respect to or otherwise sell, such shares in connection
with any vote to approve a Business Combination with respect thereto, a vote to amend the provisions of the Company’s Amended
and Restated Certificate of Incorporation, or a tender offer by the Company prior to a Business Combination.


 


14.     
The undersigned hereby agrees to not propose, or vote in favor of, an amendment to the Company’s Amended and Restated Certificate
of Incorporation with respect to the Company’s pre-Business Combination activities prior to the consummation of a Business
Combination unless the Company offers holders of IPO Shares the right to receive their pro rata portion of the funds then held
in the Trust Fund.


 


15.       
In connection with Section 5-1401 of the General Obligations Law of the State of New York, this letter agreement shall be governed
by, and construed in accordance with, the laws of the State of New York without regard to principles of conflicts of law that would
result in the application of the substantive law of another jurisdiction.  The parties hereto agree that any action, proceeding
or claim arising out of or relating in any way to this letter agreement shall be resolved through final and binding arbitration
in accordance with the International Arbitration Rules of the American Arbitration Association (“AAA”).  The
arbitration shall be brought before the AAA International Center for Dispute Resolution’s offices in New York City, New York,
will be conducted in English and will be decided by a panel of three arbitrators selected from the AAA Commercial Disputes Panel
and that the arbitrator panel’s decision shall be final and enforceable by any court having jurisdiction over the party from
whom enforcement is sought.  The cost of such arbitrators and arbitration services, together with the prevailing party’s
legal fees and expenses, shall be borne by the non-prevailing party or as otherwise directed by the arbitrators. 


  


16.      
As used herein, (i) a “Business Combination” shall mean a merger, share exchange, asset acquisition,
contractual arrangement, share purchase, recapitalization, reorganization or other similar business combination with one or more
businesses or entities; (ii) “Insiders” shall mean all officers, directors and shareholders of the Company
immediately prior to the IPO; (iii) “Insider Shares” shall mean all of the shares of Common Stock of
the Company acquired by an Insider prior to the IPO and any shares of Common Stock underlying the Private Units; (iv) “IPO
Shares” shall mean the shares of Common Stock issued in the Company’s IPO; (v) “Private Units”
shall mean (x) the Units purchased in the private placement taking place simultaneously with the consummation of the Company’s
IPO and (y) the additional Units that may be purchased in connection with the exercise of the over-allotment option by the underwriters
in the IPO as described in the Registration Statement; (vi) “Registration Statement” means the registration
statement on Form S-1 filed by the Company with respect to the IPO; and (vii) “Trust Fund” shall mean
the trust fund into which a portion of the net proceeds of the Company’s IPO will be deposited.


 


17.      
Any notice, consent or request to be given in connection with any of the terms or provisions of this letter agreement shall be
in writing and shall be sent by express mail or similar private courier service, by certified mail (return receipt requested),
by hand delivery or facsimile transmission.


 






    4


     


    

 


If to the Representative:


 


Chardan Capital Markets, LLC


17 State Street, Suite 1600


New York, NY 10004


Attn: George Kaufman


Facsimile: (646) 465-9039


 


with a copy (which copy shall not constitute
notice) to:


 


Scarinci Hollenbeck, LLC


3 Park Avenue, 15th Floor


New York, NY 10016


Attn: Dan Brecher


Fax No.: (212) 808-4155


 


If to the Company:


 


Mountain Crest Acquisition Corp


311 West 43rd Street, 12 Floor


New York, NY 10036


Attn:  Suying Liu,  Chief
Executive Officer


 


with a copy (which copy shall not constitute
notice) to:


 


Loeb & Loeb LLP


345 Park Avenue


New York, NY 10154


Attn: Giovanni Caruso, Esq.


Facsimile: (212) 504-3013


 


18.      
No party hereto may assign either this letter agreement or any of its rights, interests, or obligations hereunder without the prior
written consent of the other party. Any purported assignment in violation of this paragraph shall be void and ineffectual and shall
not operate to transfer or assign any interest or title to the purported assignee. This letter agreement shall be binding on the
parties hereto and any successors and assigns thereof.


 


19.      
The undersigned acknowledges and understands that the Underwriters and the Company will rely upon the agreements, representations
and warranties set forth herein in proceeding with the IPO.


 


[Signature Page Follows]


  






    5


     


    

 


	 	
        Sincerely,

        

	 	 
	 	By:	 /s/ Wenhua Zhang
	 	 	Name of Insider: Wenhua Zhang


  


[SIGNATURE PAGE TO LETTER AGREEMENT]


  








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