Exhibit 4.1


 


NUMBER UNITS

U-


 


SEE REVERSE FOR CERTAIN

DEFINITIONS


 


CUSIP


 


TETRAGON ACQUISITION CORPORATION I


 


UNITS CONSISTING OF ONE SHARE OF CLASS A COMMON
STOCK AND

ONE-THIRD OF ONE REDEEMABLE WARRANT, EACH WHOLE WARRANT ENTITLING THE HOLDER TO PURCHASE ONE SHARE OF CLASS A COMMON STOCK


 


THIS CERTIFIES THAT                      is the owner of                   Units.


 


Each Unit (“Unit”) consists of one (1) share
of Class A common stock, par value $0.0001 per share (“Class A Common Stock”), of Tetragon Acquisition Corporation
I, a Delaware corporation (the “Company”), and one-third (1/3) of one redeemable warrant (each whole warrant
exercisable for one share of Class A common stock) (each whole warrant a “Warrant”). Each Warrant entitles the
holder to purchase one (1) share of Class A Common Stock (subject to adjustment) for $11.50 per share (subject to adjustment). Only whole
Warrants are exercisable. Each Warrant will become exercisable on the later of (i) thirty (30) days after the Company’s completion
of an initial merger, capital stock exchange, asset acquisition, stock purchase, reorganization or other similar business combination
with one or more businesses (each a “Business Combination”), and (ii) twelve (12) months from the closing of
the Company’s initial public offering, and will expire unless exercised before 5:00 p.m., New York City Time, on the date that is
five (5) years after the date on which the Company completes its initial Business Combination, or earlier upon redemption or liquidation.
The shares of Class A Common Stock and Warrants comprising the Units represented by this certificate are not transferable separately prior
to                     , 2021, unless BofA Securities, Inc. and J.P. Morgan Securities LLC elect to allow separate trading earlier, subject to the Company’s
filing of a Current Report on Form 8-K with the Securities and Exchange Commission containing an audited balance sheet reflecting the
Company’s receipt of the gross proceeds of its initial public offering and issuing a press release announcing when separate trading
will begin. No fractional Warrants will be issued upon separation of the Units and only Warrants will trade. The terms of the Warrants
are governed by a Warrant Agreement, dated as of                    , 2021 (the “Warrant Agreement”), between the Company and Continental
Stock Transfer & Trust Company, as Warrant Agent, and are subject to the terms and provisions contained therein, all of which terms
and provisions the holder of this certificate consents to by acceptance hereof. Copies of the Warrant Agreement are on file at the office
of the Warrant Agent at One State Street, 30th Floor, New York, New York 10004, and are available to any Warrant holder on
written request and without cost.


 


Upon the consummation of the Business Combination,
the Units represented by this certificate will automatically separate into the Class A Common Stock and Warrants comprising such Units.


 


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


 


This certificate shall be governed by and construed
in accordance with the laws of the State of New York.


 


Witness the facsimile signature
of its duly authorized officers. 





 


	[Title]	 	[Title]
	 	 	 
	 	 	 
	 	 	 






 




     


     


    

 


TETRAGON ACQUISITION
CORPORATION I


 


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


 


The following abbreviations, when used in the inscription on the face
of this certificate, shall be construed as though they were written out in full according to applicable laws or regulations:


 


	TEN COM	— 	as tenants in common	 	UNIF GIFT MIN ACT	—	 	Custodian	 
	 	 	 	 	 	 	(Cust)	 	(Minor)
	TEN ENT	—	as tenants by the entireties	 	 	 	 	 	 
	 	 	 	 	 	 	Under Uniform Gifts to Minors Act
	JT TEN	—	as joint tenants with right of survivorship 	 	 	 	 
	 	 	and not as tenants in common	 	 	 	(State)


 


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


 


For value received, ______________
hereby sell(s), assign(s) and transfer(s) unto ________________


 


PLEASE INSERT
SOCIAL SECURITY OR

OTHER

IDENTIFYING NUMBER OF ASSIGNEE


 


 





 



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


 





 



 





 



 





 



 


______________ Units represented
by the within Certificate, and do(es) hereby irrevocably constitute and appoint


 


________________ Attorney to transfer the said Units on the books of the within named
Company with full power of substitution in the premises.


 


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



 






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	Signature(s) Guaranteed:	 
	 	 
	 	 
	THE SIGNATURE(S) MUST BE
GUARANTEED BY AN ELIGIBLE GUARANTOR INSTITUTION (BANKS, STOCKBROKERS, SAVINGS AND LOAN ASSOCIATIONS AND CREDIT UNIONS WITH MEMBERSHIP
IN AN APPROVED SIGNATURE GUARANTEE MEDALLION PROGRAM, PURSUANT TO S.E.C. RULE 17Ad-15 (OR ANY SUCCESSOR RULE) UNDER THE SECURITIES EXCHANGE
ACT OF 1934, AS AMENDED).	 






 


In each case, as more fully described in the Company’s final
prospectus dated                   , 2021, the holder(s) of this certificate shall be entitled to receive a pro-rata portion of certain funds held in the
trust account established in connection with the Company’s initial public offering only in the event that (i) the Company redeems
the shares of Class A Common Stock sold in its initial public offering and liquidates because it does not consummate an initial business
combination by                   , 2023, or by such later date approved by the Company’s stockholders in accordance with the Company’s amended
and restated certificate of incorporation, (ii) the Company redeems the shares of Class A Common Stock sold in its initial public offering
in connection with a stockholder vote to amend the Company’s amended and restated certificate of incorporation (A) to modify the
substance or timing of the Company’s obligation to allow redemption in connection with the Company’s initial business combination
or to redeem 100% of the shares of Class A Common Stock sold in its initial public offering if it does not complete its initial business
combination by                   , 2023, or (B) with respect to any other provision relating to the holder(s) rights or pre-initial business combination
activity, or (iii) if the holder(s) seek(s) to redeem for cash his, her, its or their respective shares of Class A Common Stock in connection
with a tender offer (or proxy solicitation, solely in the event the Company seeks stockholder approval of the proposed initial business
combination) setting forth the details of a proposed initial business combination. In no other circumstances shall the holder(s) have
any right or interest of any kind in or to the trust account.


 


 


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