Exhibit 10.2

LETTER AGREEMENT

REGARDING PLEDGE, TRANSFER AND ASSIGNMENT OF

SERIES D PREFERRED STOCK AND WARRANTS

This Letter Agreement (this “Agreement”) is entered into as of June 30, 2026, by and among:

(1) Big Digital Energy, Inc., a Nevada corporation (the “Company”);

(2) Six Thirty AI, LLC, a Texas limited liability company (the “Purchaser”); and

(3) YA II PN, LTD., a Cayman Islands exempt limited company, in its capacity as administrative agent and collateral agent for the Lenders (as defined below) under the Loan Documents (as defined below) (the “Agent” and, together with the Company and the Purchaser, the “Parties”).

RECITALS

WHEREAS, the Company and the Purchaser are parties to that certain Securities Purchase Agreement, dated as of or about the date hereof (as amended, restated, supplemented, or otherwise modified from time to time, the “SPA”), pursuant to which the Purchaser agreed to purchase, and the Company agreed to issue and sell, 16,700 shares of the Company’s Series D Convertible Preferred Stock (the “Preferred Shares”) and a warrant to purchase shares of Common Stock equal to 50% of the Preferred Shares purchased by the Purchaser (the “Warrants”);

WHEREAS, the SPA, the Warrants, the Certificate of Designations for the Series D Convertible Preferred Stock, the Registration Rights Agreement, and all other documents and agreements contemplated thereby are collectively referred to herein as the “Transaction Documents”;

WHEREAS, the Purchaser and certain affiliates of the Purchaser (collectively with the Purchaser, the “Borrowers”) have entered into that certain Loan and Guaranty Agreement, dated as of or about the date hereof (as amended, restated, supplemented, or otherwise modified from time to time, the “Loan Agreement”), with the Agent and the lenders party thereto from time to time (the “Lenders”);

WHEREAS, in connection with the Loan Agreement, the Purchaser has entered into that certain Pledge and Security Agreement, dated as of or about the date hereof (as amended, restated, supplemented, or otherwise modified from time to time, the “Pledge Agreement” and, together with the Loan Agreement and all other documents and agreements executed in connection therewith, the “Loan Documents”), pursuant to which the Purchaser has granted to the Agent, for the ratable benefit of the Lenders, a security interest in and pledge of, among other collateral, the Preferred Shares and the Warrants;

[Signature Page to Letter Agreement]

WHEREAS, pursuant to the Loan Agreement, the Warrants are to be transferred and assigned to the Lenders ratably on the closing date as a commitment fee (the “Warrant Assignment”);

WHEREAS, pursuant to the Loan Agreement, each Lender has the right to exchange all or any portion of the outstanding Obligations (as defined in the Loan Agreement) for shares of the Company’s Preferred Stock (the “Exchange Right”), and the Loan Documents further permit settlement using pledged Preferred Shares or Common Stock issuable upon conversion thereof, subject to transfer and resale restrictions; and

WHEREAS, the Purchaser and the Agent have requested that the Company acknowledge the foregoing arrangements and provide its consent thereto, subject to the terms and conditions set forth herein.

NOW, THEREFORE, in consideration of the mutual agreements and covenants set forth herein, and for other good and valuable consideration, the receipt and sufficiency of which are hereby acknowledged, the Parties agree as follows:

Section 1. Defined Terms.

Capitalized terms used but not otherwise defined herein shall have the meanings ascribed to them in the SPA, the Loan Agreement, or the Pledge Agreement, as applicable. In addition to the terms defined in the Recitals:

Section 2. Acknowledgment of Pledge.

The Company hereby acknowledges that it has been informed that the Purchaser will pledge the Preferred Shares and grant a security interest therein to the Agent, for the ratable benefit of the Lenders, pursuant to the Pledge Agreement, and that certificates representing the Preferred Shares will be delivered to the Agent together with blank stock powers in connection therewith.

Section 3. Consent to Pledge.

The Company hereby consents to the pledge of the Preferred Shares by the Purchaser to the Agent, for the ratable benefit of the Lenders, pursuant to the Pledge Agreement, and acknowledges that no further consent, approval, legal opinion, or notice from or to the Company shall be required in connection with such pledge.

Section 4. Advance Consent to Transfer of Preferred Shares.

The Company hereby consents in advance to any transfer of the Preferred Shares (or any portion thereof) to the Agent, any Lender, or any other Permitted Transferee, in each case:

in each case without further consent, approval, legal opinion, or notice from or to the Company being required, subject to Section 7 hereof. The Company further understands that all of the Purchaser’s rights and remedies under the Transaction Documents have been collaterally assigned to the Agent under the Pledge Agreement. Accordingly, any Permitted Transferee of Pledged Securities shall have all of the rights or a “Purchaser” or “Holder”, as applicable, under the Transaction Documents as if an original party thereto.

In addition, upon any transfer of Preferred Shares to Agent or any Lender, the Company shall as promptly as practicable, and in any event within 2 Trading Days, file a prospectus supplement to any effective registration statement covering the resale of the Common Stock underlying such Preferred Shares identifying the Agent or such Lender, as applicable, as a selling stockholder therein.

Section 5. Acknowledgment of Warrant Assignment.

The Company hereby acknowledges and understands that the Warrants issuable to the Purchaser under the SPA will be assigned and transferred by the Purchaser to the Lenders (ratably) as a commitment fee under the Loan Agreement. The Company acknowledges that such assignment is contemplated by the Loan Agreement and the SPA and does not require any additional consent or approval of the Company beyond the consent set forth in Section 6 below.

Section 6. Consent to Transfer of Warrants; Exercise of Rights.

Section 8. Transfer Agent Instructions; Cooperation.

Section 9. Representations.

Each Party hereby represents and warrants to the other Parties that (a) it has full power and authority to execute and deliver this Agreement and to perform its obligations hereunder, (b) this Agreement has been duly authorized, executed, and delivered by such Party, and (c) this Agreement constitutes a legal, valid, and binding obligation of such Party, enforceable against it in accordance with its terms, except as enforceability may be limited by applicable bankruptcy, insolvency, reorganization, moratorium, or similar laws affecting creditors’ rights generally and by general equitable principles.

The Company further represents to Agent that the Pledged Securities are, or will be on issuance, duly authorized are validly issued, fully paid and non-assessable and (ii) (A) are not subject to preemptive or similar rights, (B) are not subject to any transfer restrictions other than as set forth in the Transaction Documents. The Company hereby further agrees that Agent may rely on the representations and warranties of the COmpany in the Securities Purchase Agreement as if Agent was the recipient thereof.

Section 10. Governing Law.

This Agreement shall be governed by and construed in accordance with the laws of the State of New York, without regard to the conflicts-of-law principles thereof that would require the application of the laws of any other jurisdiction.

Section 11. Counterparts; Electronic Signatures.

This Agreement may be executed in two or more counterparts, each of which shall be deemed an original, but all of which together shall constitute one and the same instrument. Delivery of an executed counterpart of this Agreement by facsimile, electronic mail (including .pdf or any electronic signature complying with the U.S. federal ESIGN Act of 2000, the Uniform Electronic Transactions Act, or other applicable law), or other electronic transmission shall be equally effective as delivery of a manually executed counterpart.

Section 12. Entire Agreement; Amendments.

This Agreement constitutes the entire agreement among the Parties with respect to the subject matter hereof and supersedes all prior agreements and understandings, both written and oral, among the Parties with respect thereto. This Agreement may not be amended, modified, or supplemented except by a written instrument executed by each of the Parties.

Section 13. Third-Party Beneficiaries.

Each Lender is an intended third-party beneficiary of Sections 2, 3, 4, 5, 6, and 7 of this Agreement and shall be entitled to enforce the provisions thereof as if it were a party hereto. Except as expressly set forth in the immediately preceding sentence, nothing in this Agreement, express or implied, is intended to confer upon any person other than the Parties any rights or remedies hereunder.

Section 14. Notices.

All notices, requests, demands, and other communications required or permitted hereunder shall be given in the manner and to the addresses set forth in the SPA (with respect to the Company and the Purchaser) and the Loan Agreement (with respect to the Agent), or to such other address as any Party may designate by written notice to the other Parties.

IN WITNESS WHEREOF, the Parties have executed this Agreement as of the date first written above.

[Signature Page to Letter Agreement]