Exhibit 10.4


 


January 12, 2021


 


Pioneer Merger Corp.


c/o Falcon Edge Capital


660 Madison Avenue


New York, New York 10065


 


		Re:	Initial Public Offering



 


Ladies and Gentlemen:


 


This letter (this “Letter Agreement”)
is being delivered to you in accordance with the Underwriting Agreement (the “Underwriting Agreement”)
entered into by and between Pioneer Merger Corp., a Cayman Islands exempted company (the “Company”) and
Citigroup Global Markets Inc. as the underwriter (the “Underwriter”), relating to an underwritten initial
public offering (the “Public Offering”) of 40,250,000 of the Company’s units (including 5,250,000
units that may be purchased pursuant to the Underwriter’s option to purchase additional units, the “Units”),
each comprising of one of the Company’s Class A ordinary shares, par value $0.0001 per share (the “Ordinary
Shares”), and one-third of one redeemable warrant (each whole warrant, a “Warrant”). Each
Warrant entitles the holder thereof to purchase one Ordinary Share at a price of $11.50 per share, subject to adjustment. The Units
will be sold in the Public Offering pursuant to a registration statement on Form S-1 and a prospectus (the “Prospectus”)
filed by the Company with the U.S. Securities and Exchange Commission (the “Commission”). Certain capitalized
terms used herein are defined in paragraph 1 hereof.


 


In order to induce the Company and the Underwriter
to enter into the Underwriting Agreement and to proceed with the Public Offering and for other good and valuable consideration,
the receipt and sufficiency of which are hereby acknowledged, Pioneer Merger Sponsor LLC (the “Sponsor”)
and each of the undersigned (each, an “Insider” and, collectively, the “Insiders”)
hereby agree with the Company as follows:


 


1.           
Definitions. As used herein, (i) “Business Combination” shall mean a merger, share exchange,
asset acquisition, share purchase, reorganization or similar business combination with one or more businesses or entities; (ii)
 “Founder Shares” shall mean the 10,062,500 Class B ordinary shares of the Company, par value $0.0001
per share, outstanding prior to the consummation of the Public Offering; (iii) “Private Placement Warrants”
shall mean the warrants to purchase Ordinary Shares of the Company that will be acquired by the Sponsor for an aggregate purchase
price of $9,000,000 (or up to $10,050,000 if the Underwriter exercises its option to purchase additional units), or $1.50 per Warrant,
in a private placement that shall close simultaneously with the consummation of the Public Offering (including Ordinary Shares
issuable upon conversion thereof); (iv) “Public Shareholders” shall mean the holders of Ordinary Shares
included in the Units issued in the Public Offering; (v) “Public Shares” shall mean the Ordinary Shares
included in the Units issued in the Public Offering; (vi) “Trust Account” shall mean the trust account
into which a portion of the net proceeds of the Public Offering and the sale of the Private Placement Warrants shall be deposited;
(vii) “Transfer” shall mean the (a) sale of, offer to sell, contract or agreement to sell, hypothecate,
pledge, grant of any option to purchase or otherwise dispose of or agreement to dispose of, directly or indirectly, or establishment
or increase of a put equivalent position or liquidation with respect to or decrease of a call equivalent position within the meaning
of Section 16 of the Securities Exchange Act of 1934, as amended, and the rules and regulations of the Commission promulgated
thereunder with respect to, any security, (b) entry into any swap or other arrangement that transfers to another, in whole
or in part, any of the economic consequences of ownership of any security, whether any such transaction is to be settled by delivery
of such securities, in cash or otherwise, or (c) public announcement of any intention to effect any transaction specified
in clause (a) or (b); and (viii) “Charter” shall mean the Company’s Amended and Restated Memorandum
and Articles of Association, as the same may be amended from time to time.


 






     


     


    

 


2.           
Representations and Warranties.


 


(a)           
The Sponsor and each Insider, with respect to itself, herself or himself, represent and warrant to the Company that
it, she or he has the full right and power, without violating any agreement to which it, she or he is bound (including, without
limitation, any non-competition or non-solicitation agreement with any employer or former employer), to enter into this Letter
Agreement, as applicable, and to serve as an officer of the Company and/or a director on the Company’s Board of Director
(the “Board”), as applicable, and each Insider hereby consents to being named in the Prospectus, road
show and any other materials as an officer and/or director of the Company, as applicable.


 


(b)           
Each Insider represents and warrants, with respect to herself or himself, that such Insider’s biographical
information furnished to the Company (including any such information included in the Prospectus) is true and accurate in all material
respects and does not omit any material information with respect to such Insider’s background. The Insider’s questionnaire
furnished to the Company is true and accurate in all material respects. Each Insider represents and warrants that such Insider
is not subject to, or a respondent in any legal action for, any injunction, cease-and-desist order or order or stipulation to desist
or refrain from any act or practice relating to the offering of securities in any jurisdiction; such Insider has never been convicted
of, or pleaded guilty to, any crime (i) involving fraud, (ii) relating to any financial transaction or handling of funds
of another person, or (iii) pertaining to any dealings in any securities and such Insider is not currently a defendant in
any such criminal proceeding; and such Insider has never been suspended or expelled from membership in any securities or commodities
exchange or association or had a securities or commodities license or registration denied, suspended or revoked.


 


3.           
Business Combination Vote. It is acknowledged and agreed that the Company shall not enter into a definitive agreement
regarding a proposed Business Combination without the prior consent of the Sponsor. The Sponsor and each Insider, with respect
to itself or herself or himself, agrees that if the Company seeks shareholder approval of a proposed initial Business Combination,
then in connection with such proposed initial Business Combination, it, she or he, as applicable, shall vote all Founder Shares
and any Public Shares held by it, her or him, as applicable, in favor of such proposed initial Business Combination (including
any proposals recommended by the Board in connection with such Business Combination) and not redeem any Public Shares held by it,
her or him, as applicable, in connection with such shareholder approval.


 






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4.           
Failure to Consummate a Business Combination; Trust Account Waiver.


 


(a)           
The Sponsor and each Insider hereby agree, with respect to itself, herself or himself, that in the event that the
Company fails to consummate its initial Business Combination within the time period set forth in the Charter, the Sponsor and each
Insider shall take all reasonable steps to cause the Company to (i) cease all operations except for the purpose of winding
up; (ii) as promptly as reasonably possible but not more than 10 business days thereafter, redeem 100% of the Public Shares,
at a per-share price, payable in cash, equal to the aggregate amount then on deposit in the Trust Account, including interest earned
on the funds held in the Trust Account and not previously released to the Company to pay the Company’s taxes, if any (less
up to $100,000 of interest to pay dissolution expenses), divided by the number of then outstanding Public Shares, which redemption
will completely extinguish Public Shareholders’ rights as shareholders (including the right to receive further liquidation
distributions, if any); and (iii) as promptly as reasonably possible following such redemption, subject to the approval of
the Company’s remaining shareholders and the Board, liquidate and dissolve, subject in the case of clauses (ii) and
(iii) to the Company’s obligations under Cayman Islands law to provide for claims of creditors and in all cases subject to
the other requirements of applicable law. The Sponsor and each Insider agree not to propose any amendment to the Charter (i) that
would modify the substance or timing of the Company’s obligation to provide holders of the Public Shares the right to have
their shares redeemed in connection with an initial Business Combination or to redeem 100% of the Public Shares if the Company
does not complete an initial Business Combination within the required time period set forth in the Charter or (ii) with respect
to any provision relating to the rights of holders of Public Shares unless the Company provides its Public Shareholders with the
opportunity to redeem their Public Shares upon approval of any such amendment at a per-share price, payable in cash, equal to the
aggregate amount then on deposit in the Trust Account, including interest earned on the funds held in the Trust Account and not
previously released to the Company to pay taxes, if any, divided by the number of then-outstanding Public Shares.


 


(b)           
The Sponsor and each Insider, with respect to itself, herself or himself, acknowledges that it, she or he has no
right, title, interest or claim of any kind in or to any monies held in the Trust Account or any other asset of the Company as
a result of any liquidation of the Company with respect to the Founder Shares held by it, her or him, if any. The Sponsor and each
of the Insiders hereby further waive, with respect to any Founder Shares and Public Shares held by it, her or him, as applicable,
any redemption rights it, she or he may have in connection with the consummation of a Business Combination, including, without
limitation, any such rights available in the context of a shareholder vote to approve such Business Combination or a shareholder
vote to approve an amendment to the Charter (i) that would modify the substance or timing of the Company’s obligation
to provide holders of the Public Shares the right to have their shares redeemed in connection with an initial Business Combination
or to redeem 100% of the Public Shares if the Company has not consummated an initial Business Combination within the time period
set forth in the Charter or (ii) with respect to any provision relating to the rights of holders of Public Shares (although
the Sponsor and the Insiders shall be entitled to liquidation rights with respect to any Public Shares they hold if the Company
fails to consummate a Business Combination within the required time period set forth in the Charter).


 






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5.           
Lock-up; Transfer Restrictions.


 


(a)            The Sponsor and the Insiders agree that they shall not Transfer any Founder Shares (the “Founder Shares
Lock-up”) until the earliest of (A) one year after the completion of an initial Business Combination and (B) the
date following the completion of an initial Business Combination on which the Company completes a liquidation, merger, share exchange
or other similar transaction that results in all of the Company’s shareholders having the right to exchange their Ordinary
Shares for cash, securities or other property (the “Founder Shares Lock-up Period”). Notwithstanding
the foregoing, if, subsequent to a Business Combination, the closing price of the Ordinary Shares equals or exceeds $12.00 per
share (as adjusted for share sub-divisions, share capitalizations, share consolidations, reorganizations, recapitalizations and
the like) for any 20 trading days within a 30-trading day period commencing at least 150 days after the Company’s initial
Business Combination, the Founder Shares shall be released from the Founder Shares Lock-up.


 


(b)           
The Sponsor and Insiders agree that they shall not effectuate any Transfer of Private Placement Warrants or Ordinary
Shares underlying such warrants until 30 days after the completion of an initial Business Combination.


 


(c)           
Notwithstanding the provisions set forth in paragraphs 5(a) and (b), Transfers of the Founder
Shares, Private Placement Warrants and Ordinary Shares underlying the Private Placement Warrants are permitted: (a) to the
Company’s officers or directors, any affiliate or family member of any of the Company’s officers or directors, any
members or partners of the Sponsor or their affiliates, any affiliates of the Sponsor, or any employees of such affiliates; (b) in
the case of an individual, by gift to a member of one of the individual’s immediate family or to a trust, the beneficiary
of which is a member of the individual’s immediate family, an affiliate of such person or to a charitable organization; (c) in
the case of an individual, by virtue of laws of descent and distribution upon death of the individual; (d) in the case of
an individual, pursuant to a qualified domestic relations order; (e) by private sales or transfers made in connection with
any forward purchase agreement or similar arrangement or in connection with the consummation of a Business Combination at prices
no greater than the price at which the Founder Shares, Private Placement Warrants or Ordinary Shares, as applicable, were originally
purchased; (f) by virtue of the Sponsor’s organizational documents upon liquidation or dissolution of the Sponsor; (g) to
the Company for no value for cancellation in connection with the consummation of an initial Business Combination; (h) in the
event of the Company’s liquidation prior to the completion of a Business Combination; or (i) in the event of completion
of a liquidation, merger, share exchange or other similar transaction which results in all of the Company’s Public Shareholders
having the right to exchange their Ordinary Shares for cash, securities or other property subsequent to the completion of an initial
Business Combination; provided, however, that in the case of clauses (a) through (f) these permitted transferees
must enter into a written agreement agreeing to be bound by the transfer restrictions set forth in this Agreement.


 


(d)           
During the period commencing on the effective date of the Underwriting Agreement and ending 180 days after such date,
the Sponsor and each Insider shall not, without the prior written consent of the Underwriter, Transfer any Units, Ordinary Shares,
Warrants or any other securities convertible into, or exercisable or exchangeable for, Ordinary Shares held by it, her or him,
as applicable, subject to certain exceptions enumerated in Section 5(g) of the Underwriting Agreement.


 






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6.           
Remedies. The Sponsor and each of the Insiders hereby agree and acknowledge that (i) the Underwriter and the Company
would be irreparably injured in the event of a breach by the Sponsor or such Insider of its, her or his obligations, as applicable
under paragraphs 3, 4, 5, 7, 10 and 11, (ii) monetary damages may not be an adequate
remedy for such breach and (iii) the non-breaching party shall be entitled to injunctive relief, in addition to any other
remedy that such party may have in law or in equity, in the event of such breach.


 


7.           
Payments by the Company. Except as disclosed in the Prospectus, neither the Sponsor nor any affiliate of the Sponsor
nor any director or officer of the Company nor any affiliate of the officers shall receive from the Company any finder’s
fee, reimbursement, consulting fee, monies in respect of any payment of a loan or other compensation prior to, or in connection
with any services rendered in order to effectuate the consummation of the Company’s initial Business Combination (regardless
of the type of transaction that it is).


 


8.            
Director and Officer Liability Insurance. The Company will use commercially reasonable efforts to maintain an insurance
policy or policies providing directors’ and officers’ liability insurance, and the Insiders shall be covered by such
policy or policies, in accordance with its or their terms, to the maximum extent of the coverage available for any of the Company’s
directors or officers.


 


9.           
Termination. This Letter Agreement shall terminate on the earlier of (i) the expiration of the Founder Shares
Lock-up Period and (ii) the liquidation of the Company.


 


10.         
Indemnification. In the event of the liquidation of the Trust Account upon the failure of the Company to consummate
its initial Business Combination within the time period set forth in the Charter, the Sponsor (the “Indemnitor”)
agrees to indemnify and hold harmless the Company against any and all loss, liability, claim, 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) to which the Company may become subject as a result of any claim by (i) any third
party for services rendered or products sold to the Company (except for the Company’s independent auditors) or (ii) any
prospective target business with which the Company has discussed entering into a transaction agreement (a “Target”);
provided, however, that such indemnification of the Company by the Indemnitor (x) shall apply only to the extent
necessary to ensure that such claims by a third party for services rendered or products sold to the Company or a Target do not
reduce the amount of funds in the Trust Account to below the lesser of (i) $10.00 per Public Share and (ii) the actual amount
per Public Share held in the Trust Account as of the date of the liquidation of the Trust Account if less than $10.00 per Public
Share due to reductions in the value of the trust assets, in each case net of interest that may be withdrawn to pay the Company’s
tax obligations, (y) shall not apply to any claims by a third party or Target who executed a waiver of any and all rights
to the monies held in the Trust Account (whether or not such waiver is enforceable) and (z) shall not apply to any claims
under the Company’s indemnity of the Underwriter against certain liabilities, including liabilities under the Securities
Act of 1933, as amended. The Indemnitor shall have the right to defend against any such claim with counsel of its choice reasonably
satisfactory to the Company if, within 15 days following written receipt of notice of the claim to the Indemnitor, the Indemnitor
notifies the Company in writing that it shall undertake such defense.


 






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11.         
Forfeiture of Founder Shares. To the extent that the Underwriter does not exercise its option to purchase additional
Units within 45 days from the date of the Prospectus in full (as further described in the Prospectus), the Sponsor agrees to automatically
surrender to the Company for no consideration, for cancellation at no cost, an aggregate number of Founder Shares so that the number
of Founder Shares will equal of 20% of the sum of the total number of Ordinary Shares and Founder Shares outstanding at such time.
The Sponsor and Insiders further agree that to the extent that the size of the Public Offering is increased or decreased, the Company
will effect a share capitalization or a share repurchase, as applicable, with respect to the Founder Shares immediately prior to
the consummation of the Public Offering in such amount as to maintain the number of Founder Shares at 20% of the sum of the total
number of Ordinary Shares and Founder Shares outstanding at such time.


 


12.         
Entire Agreement. This Letter Agreement constitutes the entire agreement and understanding of the parties hereto
in respect of the subject matter hereof and supersedes all prior understandings, agreements or representations by or among the
parties hereto, written or oral, to the extent they relate in any way to the subject matter hereof or the transactions contemplated
hereby. This Letter Agreement may not be changed, amended, modified or waived (other than to correct a typographical error) as
to any particular provision, except by a written instrument executed by all parties hereto.


 


13.         
Assignment. 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 parties. 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 Sponsor, each of the Insiders and each of their respective successors, heirs, personal representatives
and assigns and permitted transferees.


 


14.         
Counterparts. This Letter Agreement may be executed in any number of original, electronic or facsimile counterparts,
and each of such counterparts shall for all purposes be deemed to be an original, and all such counterparts shall together constitute
but one and the same instrument.


 


15.         
Effect of Headings. The paragraph headings herein are for convenience only and are not part of this Letter Agreement
and shall not affect the interpretation thereof.


 


16.         
Severability. This Letter Agreement shall be deemed severable, and the invalidity or unenforceability of any term
or provision hereof shall not affect the validity or enforceability of this Letter Agreement or of any other term or provision
hereof. Furthermore, in lieu of any such invalid or unenforceable term or provision, the parties hereto intend that there shall
be added as a part of this Letter Agreement a provision as similar in terms to such invalid or unenforceable provision as may be
possible and be valid and enforceable.


 






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17.         
Governing Law. This Letter Agreement shall be governed by and construed and enforced in accordance with the laws
of the State of New York, without giving effect to conflicts of law principles that would result in the application of the substantive
laws of another jurisdiction. The parties hereto (i) all agree that any action, proceeding, claim or dispute arising out of,
or relating in any way to, this Letter Agreement shall be brought and enforced in the courts of New York City, in the State of
New York, and irrevocably submit to such jurisdiction and venue, which jurisdiction and venue shall be exclusive, (ii) waive
any objection to such exclusive jurisdiction and venue or that such courts represent an inconvenient forum and (iii) waive any
right to a trial by jury in any action, suit or proceeding to enforce or defend any right under this Letter Agreement, and agree
that any such action, suit or proceeding will be tried before a court and not before a jury.


 


18.         
Notices. 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.


 


[Signature Pages Follow]


 









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	 	Sincerely,
	 	 
	 	PIONEER MERGER SPONSOR LLC
	 	 
	 	By:	 /s/ Scott Carpenter
	 	 	Name: Scott Carpenter
	 	 	Title: Chief Operating Officer






 


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	 	/s/ Rick Gerson
	 	Rick Gerson




 


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	 	/s/ Ryan Khoury
	 	Ryan Khoury







 


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	 	/s/ Scott Carpenter
	 	Scott Carpenter







 


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	 	/s/ Matthew Corey
	 	Matthew Corey







 


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	 	/s/ Mitchell Caplan
	 	Mitchell Caplan







 


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	 	/s/ Todd Davis
	 	Todd Davis







 


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	 	/s/ Jonathan Christodoro
	 	Jonathan Christodoro







 


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	 	/s/ Oscar Salazar
	 	Oscar Salazar







 


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Acknowledged and Agreed:


 


PIONEER MERGER CORP.


 


	By:	/s/ Scott Carpenter 	 
	 	Name:	Scott Carpenter	 
	 	Title:	Chief Operating Officer	 



 


[Signature Page
to Letter Agreement]