SECURITIES PURCHASE AGREEMENT

This Securities Purchase Agreement (this “Agreement”) is dated as of May 20, 2026, between Rubico Inc., a company incorporated under the laws of the Republic of the Marshall Islands (the “Company”), and each purchaser identified on the signature pages hereto (each, including its successors and assigns, a “Purchaser” and collectively the “Purchasers”).

WHEREAS, subject to the terms and conditions set forth in this Agreement and pursuant to an effective registration statement under the Securities Act (as defined below), the Company desires to issue and sell to each Purchaser, and each Purchaser, severally and not jointly, desires to purchase from the Company, securities of the Company as more fully described in this Agreement.

NOW, THEREFORE, IN CONSIDERATION of the mutual covenants contained in this Agreement, and for other good and valuable consideration the receipt and adequacy of which are hereby acknowledged, the Company and each Purchaser agree as follows:

ARTICLE I. DEFINITIONS

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APERTURE AC

835 Wilshire Boulevard, 5th Floor

Los Angeles, CA, 90017

May 20, 2026

Aperture Sponsor LLC

835 Wilshire Boulevard, 5th Floor

Los Angeles, CA, 90017

	Re:	Administrative Services Agreement

Ladies and Gentlemen:

This letter agreement by and between Aperture AC (the “Company”) and Aperture Sponsor LLC (the “Services Provider” and Sponsor”), dated as of the date hereof, will confirm our agreement that, commencing on the date the securities of the Company are first listed on the Nasdaq Global Market (the “Listing Date”), pursuant to a Registration Statement on Form S-1 and prospectus filed with the U.S. Securities and Exchange Commission (the “Registration Statement”) and continuing until the earlier of the consummation by the Company of an initial business combination and the Company’s liquidation (in each case as described in the Registration Statement) (such earlier date hereinafter referred to as the “Termination Date”):

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THE EXCHANGE CONTEMPLATED HEREIN IS INTENDED TO COMPORT WITH THE REQUIREMENTS OF SECTION 3(a)(9) OF THE SECURITIES ACT OF 1933, AS AMENDED.

EXCHANGE AGREEMENT

This Exchange Agreement (this “Agreement”) is entered into as of May 21, 2026 (the “Effective Date”) by and between Streeterville Capital, LLC, a Utah limited liablity company (“Lender”), and Jaguar Health, Inc., a Delaware corporation (“Borrower”). Capitalized terms used in this Agreement without definition shall have the meanings given to them in the Royalty Interest (as defined below).

A. Company previously sold and issued to Investor that certain Royalty Interest dated August 24, 2022 (the “Royalty Interest”) pursuant to that certain Royalty Interest Purchase Agreement dated August 24, 2022 (the “Purchase Agreement,” and together with the Royalty Interest and all other documents entered into in conjunction therewith, the “Transaction Documents”).

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THE EXCHANGE CONTEMPLATED HEREIN IS INTENDED TO COMPORT WITH THE REQUIREMENTS OF SECTION 3(a)(9) OF THE SECURITIES ACT OF 1933, AS AMENDED.

EXCHANGE AGREEMENT

This Exchange Agreement (this “Agreement”) is entered into as of May 21, 2026 (the “Effective Date”) by and between Streeterville Capital, LLC, a Utah limited liablity company (“Lender”), and Jaguar Health, Inc., a Delaware corporation (“Borrower”). Capitalized terms used in this Agreement without definition shall have the meanings given to them in the Royalty Interest (as defined below).

A. Company previously sold and issued to Investor that certain Royalty Interest dated August 24, 2022 (the “Royalty Interest”) pursuant to that certain Royalty Interest Purchase Agreement dated August 24, 2022 (the “Purchase Agreement,” and together with the Royalty Interest and all other documents entered into in conjunction therewith, the “Transaction Documents”).

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EXECUTION

Certain confidential information contained in this document, marked by [***], has been omitted

because the registrant has determined that the information (i) is not material and (ii) is the type

that the registrant treats as private or confidential.

EXhibit 10.14

AMENDMENT no. 5 TO Fund Administration and Accounting agreement

This AMENDMENT (“Amendment”) is made and entered into, as of the latest date on the signature page hereto (the “Effective Date”), by and between each entity listed on Exhibit A attached hereto (each, a “Trust”, and collectively the “Trusts” as applicable), separately and not jointly, and The bank of new york mellon (“BNY”). BNY and the Trusts are collectively referred to as the “Parties” and individually as a “Party”.

WHEREAS, the Trusts and BNY have entered into a Fund Administration and Accounting Agreement dated as of October 9, 2025 (as amended, restated, supplemented or otherwise modified from time to time, the “Agreement”); and

WHEREAS, the Trusts and BNY desire to amend the Agreement as set forth herein;

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EXECUTION

Certain confidential information contained in this document, marked by [***], has been omitted

because the registrant has determined that the information (i) is not material and (ii) is the type

that the registrant treats as private or confidential.

Exhibit 10.13

AMENDMENT No. 5 TO Transfer agency and service agreement

This AMENDMENT (“Amendment”) is made and entered into, as of the latest date on the signature page hereto (the “Effective Date”), by and between each entity listed on Appendix I hereto, separately and not jointly (each, individually, a “Trust”) and THE BANK OF NEW YORK MELLON (“BNY”). BNY and the Trusts are collectively referred to as the “Parties” and individually as a “Party”.

WHEREAS, the Trusts and BNY have entered into Transfer Agency and Service Agreement dated as of October 9, 2025 (as amended, restated, supplemented or otherwise modified from time to time, the “Agreement”); and

WHEREAS, the Trusts and BNY desire to amend the Agreement as set forth herein;

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Certain confidential information contained in this document, marked by [***], has been omitted because

the Registrant has determined that the information (i) is not material and (ii) is of the type

that the registrant treats as private or confidential.

Exhibit 10.12

AMENDMENT NO. 2 TO THE MARKETING AGENT AGREEMENT

This AMENDMENT No. 2 TO THE MARKETING AGENT AGREEMENT (the “Amendment”) dated as of April 16, 2026 (the “Effective Date”), is entered into by and between: (i) Foreside Fund Services, LLC, a Delaware limited liability company (“Foreside”); and (ii) Grayscale Investments Sponsors, LLC, acting in its capacity as sponsor (the “Sponsor”) of each entity listed on Exhibit A attached hereto (each, a “Trust”), as the same may be amended from time to time, (the “Parties”).

R E C I T A L S

WHEREAS, the Parties have entered into that certain Marketing Agent Agreement, dated as of October 22, 2025 (the “Original Agreement”);

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LIQUIDITY PROVIDER AGREEMENT

LIQUIDITY PROVIDER AGREEMENT (this “Agreement”) dated as of [ ], among: (i) [ ] (the “Liquidity Provider”); (ii) Grayscale Investments Sponsors, LLC, except as otherwise specified herein, acting in its capacity as sponsor (the “Sponsor”) of each trust listed on Schedule I attached hereto, as the same may be amended from time to time by the Sponsor (each, the applicable “Trust” or “Product” when referred to throughout the remainder of this Agreement) created under Delaware law pursuant to its applicable declaration of trust and trust agreement listed on Schedule I attached hereto between the Delaware Trust Company acting in its capacity as Trustee (the “Trustee”) and the Sponsor (each, the applicable “Trust Agreement” when referred to throughout the remainder of this Agreement), or is a Cayman Islands limited liability company created pursuant to a limited liability company agreement between the Sponsor and the shareholders of such Product (the “LLC Agreement”) and in its capacity as the engager of one or more liquidity providers (the “Liquidity Engager”

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EXECUTION

Certain confidential information contained in this document, marked by [***], has been omitted because the registrant has determined that the information (i) is not material and (ii) is the type that the registrant treats as private or confidential.

TRANSFER AGENCY AND SERVICE AGREEMENT

THIS AGREEMENT is made as of the 9th day of October, 2025, by and between each entity listed on Appendix I hereto, separately and not jointly (each, individually, a “Trust”) and THE BANK OF NEW YORK MELLON, a New York corporation authorized to do a banking business having its principal office and place of business at 240 Greenwich Street, New York, New York 10286 (the “Bank”).

WHEREAS, the Trust will ordinarily issue for purchase and redeem shares of the Trust (the “Shares) only in aggregations of Shares known as “Creation Units” (currently 10,000 shares) (each a “Creation Unit”) principally in kind;

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Certain confidential information contained in this document, marked by [***], has been omitted because the registrant has determined that the information (i) is not material and (ii) is the type that the registrant treats as private or confidential.

MARKETING AGENT AGREEMENT

THIS AGREEMENT is made and entered into as of this 22nd day of October, 2025 (“Effective Date”), by and between each entity listed on Appendix I hereto, separately and not jointly (each, individually, a “Trust”), and Foreside Fund Services, LLC, a Delaware limited liability company (“Foreside”).

WHEREAS, the Trust, which is sponsored by the Grayscale Investments Sponsors, LLC (the “Sponsor”), is a statutory trust organized under the laws of the State of Delaware;

WHEREAS, the Trust has filed with the U.S. Securities and Exchange Commission (the “SEC”) a Registration Statement for the Trust under the Securities Act of 1933, as amended (the “1933 Act”);

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EXECUTION

Certain confidential information contained in this document, marked by [***], has been omitted because the registrant has determined that the information (i) is not material and (ii) is the type that the registrant treats as private or confidential.

FUND ADMINISTRATION AND ACCOUNTING AGREEMENT

THIS AGREEMENT is made as of October 9, 2025, by and between each entity listed on Exhibit A attached hereto (each a “Trust”, and collectively the “Trusts” as applicable), separately and not jointly, and The Bank of New York Mellon, a New York corporation authorized to do a banking business (“BNY”).

W I T N E S S E T H :

WHEREAS, the Trust desires to retain BNY to provide the services described herein, and BNY is willing to provide such services, all as more fully set forth below;

NOW, THEREFORE, in consideration of the mutual promises and agreements contained herein, the parties hereby agree as follows:

Definitions.

Whenever used in this Agreement, unless the context otherwise requires, the following words shall have the meanings set forth below:

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Certain confidential information contained in this document, marked by [***], has been omitted

because the registrant has determined that the information (i) is not material and (ii) is the type

that the registrant treats as private or confidential.

Exhibit 10.2

ANCHORAGE – EXCHANGE-TRADED PRODUCT (ETP) STAKING ADDENDUM

This addendum (the “ETP Staking Addendum”) to the Master Custody Service Agreement dated August 8, 2025, as amended (the “Anchorage Custody Agreement”), between the entities listed in the “Client(s)” section of the Order Form of such Anchorage Custody Agreement (each, a “Client”) and Anchorage Digital Bank N.A. (“Anchorage”), sets forth the terms pursuant to which Client may elect, pursuant to Section 2.4 of the Anchorage Custody Agreement, to receive staking as an On-Chain Service and may instruct Anchorage, by Direction and, where applicable, Authenticated Instruction, to cause certain Digital Assets held by Anchorage for Client and credited to the applicable Account to be committed (or “Staked”), in accordance with the underlying blockchain network or proto

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