Exhibit 4.2

WARRANT ASSIGNMENT, ASSUMPTION AND AMENDMENT AGREEMENT

This Warrant Assignment, Assumption and Amendment Agreement (this “Agreement”) is made as of June 25, 2026, by and among TLGY Acquisition Corporation, a Cayman Islands exempted company (“TLGY”), StablecoinX Inc., a Delaware corporation (the “Company”), and Continental Stock Transfer & Trust Company, a New York corporation (the “Warrant Agent”).

WHEREAS, TLGY and the Warrant Agent are party to that certain Warrant Agreement, dated as of November 30, 2021 (the “Warrant Agreement”);

WHEREAS, capitalized terms used herein, but not otherwise defined, shall have the meanings given to such terms in the Warrant Agreement;

WHEREAS, TLGY completed its initial public offering on December 3, 2021 (the “Offering”) and in connection therewith TLGY issued (i) 23,000,000 Units, which included up to 11,500,000 Public Warrants, with each whole Public Warrant exercisable for one Class A Ordinary Share, par value $0.0001 per share, of TLGY (each, a “TLGY Class A Share”) and with an exercise price of $11.50 per share, in the Offering; and (ii) an aggregate of 11,259,500 Private Placement Warrants, with each Private Placement Warrant being exercisable for one TLGY Class A Share and with an exercise price of $11.50 per share, in a private placement that closed simultaneously with the Offering (collectively, the “TLGY Warrants”);

WHEREAS, all of the TLGY Warrants are governed by the Warrant Agreement;

WHEREAS, on July 21, 2025, TLGY, the Company, StablecoinX Assets Inc. (“SC Assets”), StablecoinX SPAC Merger Sub LLC, a wholly-owned subsidiary of StablecoinX (“SPAC Merger Sub”), and StablecoinX Company Merger Sub, Inc., a wholly-owned subsidiary of StablecoinX (“Company Merger Sub”), entered into that certain Business Combination Agreement (as amended or supplemented from time to time, the “Business Combination Agreement” and the transactions contemplated thereby, the “Business Combination”), pursuant to which, among other things, TLGY merged with and into SPAC Merger Sub, with SPAC Merger Sub continuing as the surviving company (the “SPAC Merger”), as a result of which the holders of TLGY Class A Shares received one share of Class A common stock, par value $0.0001 per share, of StablecoinX (each, a “Company Class A Share”), for each TLGY Class A Share held by such shareholder;

WHEREAS, upon consummation of the SPAC Merger, and as provided in Section 4.4 of the Warrant Agreement, each TLGY Warrant issued and outstanding immediately prior to the SPAC Merger will no longer be exercisable for TLGY Class A Shares but instead will be exercisable (subject to the terms and conditions of the Warrant Agreement as amended hereby) for Company Class A Shares (collectively, “Company Warrants”);

WHEREAS, the board of directors of TLGY has determined that the consummation of the Business Combination constitutes a business combination contemplated under the Warrant Agreement;

WHEREAS, in connection with the SPAC Merger, TLGY desires to assign all of its right, title and interest in the Warrant Agreement to the Company and the Company wishes to accept such assignment; and

WHEREAS, Section 9.8 of the Warrant Agreement provides that TLGY and the Warrant Agent may amend the Warrant Agreement without the consent of any registered holders for the purpose of curing any ambiguity, mistake or curing, correcting or supplementing any defective provision contained int the Warrant Agreement or adding or changing any other provisions with respect to matters or questions arising under the Warrant Agreement as the parties may deem necessary or desirable and that the parties deem shall not adversely affect the interest of the registered holders.

NOW, THEREFORE, in consideration of the mutual agreements contained herein and other good and valuable consideration, the receipt and sufficiency of which are hereby acknowledged, and intending to be legally bound hereby, the parties hereto agree as follows.

“WHEREAS, in December 2021, TLGY Acquisition Corporation, a Cayman Islands exempted company (“TLGY”), consummated an initial public offering (the “Offering”) of 23,000,000 units of TLGY’s equity securities (the “Units”), each such Unit comprised of one Class A ordinary share of TLGY, par value $0.0001 per share (“TLGY Class A Shares”) and one-half of one redeemable warrant (the “Public Warrants”).

WHEREAS, on November 30, 2021, TLGY entered into that certain Sponsor Warrants Purchase Agreement (the “Sponsor Private Placement Warrants Purchase Agreements”), with TLGY Sponsors LLC, a Cayman Islands limited liability company (the “Former Sponsor”), pursuant to which the Former Sponsor purchased an aggregate of 11,259,500 warrants in connection with the closing of the Offering bearing the legend set forth in Exhibit B hereto (the “Sponsor Private Placement Warrants”) at a purchase price of $1.00 per Private Placement Warrant. Each Private Placement Warrant entitles the holder thereof to purchase one Class A ordinary share (as defined below) at a price of $11.50 per share, subject to adjustment, terms and limitations as described herein

WHEREAS, TLGY, the Company, StablecoinX Assets, Inc., a Delaware corporation (“SC Assets”), StablecoinX SPAC Merger Sub LLC, a Delaware limited liability company and a wholly-owned subsidiary of the Company (“SPAC Merger Sub”), and StablecoinX Company Merger Sub, Inc., a Delaware corporation and a wholly-owned subsidiary of the Company (“Company Merger Sub”), entered into that certain Business Combination Agreement, dated as of July 21, 2025 (as amended, the “Business Combination Agreement” and the transactions contemplated thereby, the “Business Combination”), pursuant to which, among other things, TLGY merged with and into SPAC Merger Sub (the “SPAC Merger”) with TLGY surviving the SPAC Merger as a wholly owned subsidiary of the Company. In connection with the SPAC Merger, each issued and outstanding TLGY Class A Share was exchanged for one share of Class A common stock of the Company, par value $0.0001 per share (each, a “Company Class A Share”);

WHEREAS, in connection with the Business Combination, the Company filed with the U.S. Securities and Exchange Commission (the “Commission”) a registration statement on Form S-4, File No. 333-290567 (the “Registration Statement”), and prospectus (the “Prospectus”), for the registration, under the Securities Act of 1933, as amended (the “Securities Act”), of the Company Class A Shares and the Public Warrants;

WHEREAS, on June 25, 2026, the Company, TLGY and the Warrant Agent entered into a Warrant Assignment, Assumption and Amendment Agreement (the “Warrant Assumption Agreement”), pursuant to which, among other things, TLGY assigned all of its right, title and interest in and to this Agreement to the Company, and the Company assumed all of TLGY’s liabilities and obligations under this Agreement;

WHEREAS, pursuant to the Business Combination Agreement, the Warrant Assumption Agreement and the terms of this Agreement (as amended by the Warrant Assumption Agreement), each Public Warrant was assumed by the Company and is now exercisable to purchase one Company Class A Share rather than one TLGY Class A Share;

WHEREAS, the Company desires the Warrant Agent to act on behalf of the Company, and the Warrant Agent is willing to so act, in connection with the issuance, registration, transfer, exchange, redemption and exercise of the Warrants;

WHEREAS, the Company desires to provide for the form and provisions of the Warrants, the terms upon which they shall be issued and exercised, and the respective rights, limitation of rights, and immunities of the Company, the Warrant Agent and the holders of the Warrants; and

WHEREAS, all acts and things have been done and performed which are necessary to make the Warrants, when executed on behalf of the Company and countersigned by or on behalf of the Warrant Agent (if a physical certificate is issued), as provided herein, the valid, binding and legal obligations of the Company, and to authorize the execution and delivery of this Agreement.

NOW, THEREFORE, in consideration of the mutual agreements herein contained, the parties hereto agree as follows:”

“[INTENTIONALLY OMITTED.]”

“[INTENTIONALLY OMITTED.]”

“Fractional Warrants. The Company shall not issue fractional Warrants. If a holder of Warrants would be entitled to receive a fractional Warrant, the Company shall round down to the nearest whole number of Warrants to be issued to such holder.”

“9.2. Notices. Any notice, statement or demand authorized by this Agreement to be given or made by the Warrant Agent or by the holder of any Warrant to or on the Company shall be sufficiently given when so delivered if by hand or overnight delivery, by pdf via email, or if sent by certified mail or private courier service within five (5) days after deposit of such notice, postage prepaid, addressed (until another address is filed in writing by the Company with the Warrant Agent), as follows:

StablecoinX Inc.

6160 Warren Parkway, Suite 100

Frisco, TX 75034

Attention: Edward Chen

E-mail: tchen@stablecoinx.com

Any notice, statement or demand authorized by this Agreement to be given or made by the holder of any Warrant or by the Company to or on the Warrant Agent shall be sufficiently given when so delivered if by hand or overnight delivery, by pdf via email, or if sent by certified mail or private courier service within five (5) days after deposit of such notice, postage prepaid, addressed (until another address is filed in writing by the Warrant Agent with the Company), as follows:

Continental Stock Transfer & Trust Company

One State Street, 30th Floor

New York, NY 10004

Attention: Compliance Department

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

Perkins Coie LLP

1155 Avenue of the Americas, 22^nd Floor

New York, New York 10036

Attention: Elliott Smith

E-mail: ElliottSmith@perkinscoie.com”

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IN WITNESS WHEREOF, the parties hereto have duly executed this Agreement, all as of the date first written above.

[Signature Page to Warrant Assumption Agreement]