Material Agreement (Form 8-K)

Item 1.01. Entry into a Material Definitive Agreement.

Membership Interests Purchase Agreement

On April 15, 2026, Soluna Digital Inc. (the "Purchaser"), a wholly owned subsidiary of Soluna Holdings, Inc. (the "Company"), entered into a Membership Interests Purchase Agreement (the "MIPA"), with Soluna SLC Fund I Projects Holdco LLC (the "Seller") and Soluna DVSL JVCo, LLC, a Delaware limited liability company (the "Dorothy 1A Project Company"), pursuant to which the Purchaser acquired 85.4% of the issued and outstanding Class B Membership Interests in the Dorothy 1A Project Company from the Seller. The Dorothy 1A Project Company owns a wind-powered data center campus in Silverton, Texas focused on bitcoin hosting. The MIPA contains customary representations and warranties of the Seller and the Purchaser.

The closing of the acquisition (the "Closing") occurred simultaneously with the execution of the MIPA on April 15, 2026. At the Closing, the Purchaser paid $6.0 million to the Seller and an additional $10.5 million payment is due to the Seller no later than July 1, 2026. Upon the Closing, the Purchaser owns 100% of the issued and outstanding membership interests of the Dorothy 1A Project Company.

Securities Purchase Agreement and Promissory Note

In connection with the MIPA, on April 15, 2026, the Company entered into a Securities Purchase Agreement (the "SPA") with YA II PN, LTD. (the "Lender"), pursuant to which the Company issued to the Lender a Promissory Note (the "Note") payable to the Lender, providing for an unsecured loan in the aggregate principal amount of up to $12,000,000 (the "Principal Amount"). The outstanding Principal Amount will mature on May 15, 2027 (the "Maturity Date") and bears interest at a rate per annum of 5%, based on a 365-day year, which interest rate shall increase to a rate per annum of 18% upon the occurrence of an Event of Default (as defined in the Note) for so long as such event remains uncured. Under the Note, the Company is required to make monthly payments ("Amortization Payments") of $1.2 million per month, beginning sixty (60) days after closing until the Note is repaid in full. Each Amortization Payment shall include a 5% premium of the principal amount of such payment.

The Company may, upon at least one Business Day's prior written notice to the Lender, prepay the outstanding Principal Amount and an additional 5% of such Principal Amount (solely in respect of a redemption in full), and any accrued and unpaid interest, at any time prior to the Maturity Date. If the Company consummates a financing transaction, or series of financing transactions within a thirty (30) day period, with aggregate gross proceeds in excess of $20 million (excluding any (i) transaction with the Lender or its affiliates, (ii) sales under the At the Market Offering Agreement entered into between the Company and H.C. Wainwright & Co., LLC on April 29, 2025, (iii) issuance under the Standby Equity Purchase Agreement entered into between the Company and the Lender on August 12, 2024 or the Standby Equity Purchase Agreement entered into between the Company and the Lender on March 24, 2026, or (iv) exercises of options, warrants, or convertible securities outstanding as of April 15, 2026), then, unless waived by the Lender, the Company shall be required to redeem the Note in an amount equal to (a) 20% of the outstanding Principal Amount and (b) all accrued and unpaid interest on the Note.

The Note includes customary representations, warranties and covenants and sets forth certain events of default after which the outstanding Principal Amount may be declared immediately due and payable and sets forth certain types of bankruptcy or insolvency events of default involving the Company after which the outstanding Principal Amount becomes automatically due and payable.

Guaranty

Pursuant to the SPA, Soluna Wind Holding, Inc., a wholly owned subsidiary of the Company (the "Guarantor"), entered into a Guaranty, dated April 15, 2026 (the "Guaranty"). Pursuant to the terms of the Guaranty, the Guarantor agreed to guarantee the complete performance and fulfillment of the Company's obligations under the SPA and the Note.