MKTY / Mechanical Technology, Inc. - Zgłoszenia SEC, Raport roczny, o pełnomocnictwie

Soluna Acquires Full Ownership of Project Dorothy 1B, Completing Equity Consolidation of Dorothy 1 Campus Approximately $8.8M Acquisition Closes the Vertically Integrated Ownership of Dorothy 1, Positioning the campus for AI conversion

Exhibit 99.1 Soluna Acquires Full Ownership of Project Dorothy 1B, Completing Equity Consolidation of Dorothy 1 Campus Approximately $8.8M Acquisition Closes the Vertically Integrated Ownership of Dorothy 1, Positioning the campus for AI conversion ALBANY, NY, May 20, 2026 – Soluna Holdings, Inc. (“Soluna” or the “Company”) (NASDAQ: SLNH), a developer of green data centers for intensive computing

MEMBERSHIP INTERESTS PURCHASE AGREEMENT

Exhibit 10.1 Execution Version MEMBERSHIP INTERESTS PURCHASE AGREEMENT This Membership Interests Purchase Agreement (this “Agreement”) is entered into as of May 19, 2026 (the “Effective Date”), by and among Navitas West Texas Investments SPV, LLC, a Delaware limited liability company (the “Seller”), Soluna Digital Inc., a Nevada corporation (the “Purchaser”), Navitas Global LLC (“Guarantor”) solel

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 19, 2026 SOLUNA HOLDINGS, INC

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 19, 2026 SOLUNA HOLDINGS, INC. (Exact name of Registrant as Specified in Its Charter) Nevada 001-40261 14-1462255 (State or Other Jurisdiction of Incorporation) (Commission File N

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 18, 2026 SOLUNA HOLDINGS, INC

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 18, 2026 SOLUNA HOLDINGS, INC. (Exact name of Registrant as Specified in Its Charter) Nevada 001-40261 14-1462255 (State or Other Jurisdiction of Incorporation) (Commission File N

Soluna Reports Q1’26 Results; Revenue Grows 58% Year-Over-Year and 4th Consecutive Quarter Sequentially Completes Kati 1A Ahead of Schedule, Advances Kati 2 AI JV

Exhibit 99.1 Soluna Reports Q1’26 Results; Revenue Grows 58% Year-Over-Year and 4th Consecutive Quarter Sequentially Completes Kati 1A Ahead of Schedule, Advances Kati 2 AI JV ALBANY, NY, May 18, 2026 - Soluna Holdings, Inc. (“Soluna” or the “Company”) (NASDAQ: SLNH), a developer of green data centers for intensive computing applications, including Bitcoin mining and AI, announced its financial re

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q

Table of contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended March 31, 2026 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number: 001-40261 So

Soluna Holdings, Inc. 2,459,400 Shares of Common Stock

Filed Pursuant to Rule 424(b)(3) Registration No. 333-295416 PROSPECTUS Soluna Holdings, Inc. 2,459,400 Shares of Common Stock This prospectus relates to the resale of 2,459,400 shares of common stock, par value $0.001 per share (the “common stock”), of Soluna Holdings, Inc. (the “Company,” “we,” “our” or “us”) by the selling stockholders listed in this prospectus (the “Selling Stockholders”) comp

Soluna Announces Monthly Business Update

Exhibit 99.1 Soluna Announces Monthly Business Update ALBANY, NY, May 7, 2026 – Soluna Holdings, Inc. (“Soluna” or the “Company”) (NASDAQ: SLNH), a developer of green data centers for intensive computing applications, including Bitcoin mining and AI, announced its April 2026 project site-level operations, developments, and updates. The Company has provided the following Corporate and Site Updates.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 7, 2026 SOLUNA HOLDINGS, INC.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 7, 2026 SOLUNA HOLDINGS, INC. (Exact name of Registrant as Specified in Its Charter) Nevada 001-40261 14-1462255 (State or Other Jurisdiction of Incorporation) (Commission File Nu

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): April 30, 2026 SOLUNA HOLDINGS, I

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): April 30, 2026 SOLUNA HOLDINGS, INC. (Exact name of Registrant as Specified in Its Charter) Nevada 001-40261 14-1462255 (State or Other Jurisdiction of Incorporation) (Commission File

Soluna Regains Compliance with Nasdaq Listing Requirements

Exhibit 99.1 Soluna Regains Compliance with Nasdaq Listing Requirements ALBANY, NY, May 1, 2026 – Soluna Holdings, Inc. (“Soluna” or the “Company”) (NASDAQ: SLNH), a developer of green data centers for intensive computing applications such as AI and Bitcoin mining, today announced that it has received notice from The Nasdaq Stock Market LLC (“Nasdaq”) that the Company has regained compliance with

Security Type

Calculation of Filing Fee Tables S-3 Soluna Holdings, Inc Table 1: Newly Registered and Carry Forward Securities ☐Not Applicable Security Type Security Class Title Fee Calculation or Carry Forward Rule Amount Registered Proposed Maximum Offering Price Per Unit Maximum Aggregate Offering Price Fee Rate Amount of Registration Fee Carry Forward Form Type Carry Forward File Number Carry Forward Initial Effective Date Filing Fee Previously Paid in Connection with Unsold Securities to be Carried Forward Newly Registered Securities Fees to be Paid 1 Equity Common Stock, par value $0.

As filed with the Securities and Exchange Commission on April 29, 2026

As filed with the Securities and Exchange Commission on April 29, 2026 Registration No.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): April 28, 2026 SOLUNA HOLDINGS, I

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): April 28, 2026 SOLUNA HOLDINGS, INC. (Exact name of Registrant as Specified in Its Charter) Nevada 001-40261 14-1462255 (State or Other Jurisdiction of Incorporation) (Commission File

Soluna and Sazmining Announce 3 MW Bitcoin Mining Operation at Project Dorothy 1B Marks Sazmining’s second U.S. deployment, with potential to scale subject to customer demand and capacity availability

Exhibit 99.1 Soluna and Sazmining Announce 3 MW Bitcoin Mining Operation at Project Dorothy 1B Marks Sazmining’s second U.S. deployment, with potential to scale subject to customer demand and capacity availability ALBANY, NY, April 28, 2026 – Soluna Holdings, Inc. (“Soluna” or the “Company”) (NASDAQ: SLNH), a developer of green data centers for intensive computing applications, including Bitcoin m

Soluna Holdings, Inc. 1,350,000 Common Warrants 1 to Purchase Up to 1,350,000 Shares of Common Stock 650,000 Common Warrants 2 to Purchase Up to 650,000 Shares of Common Stock 700,000 Pre-Funded Warrants to Purchase Up to 700,000 Shares of Common Sto

Filed Pursuant to Rule 424(b)(3) Registration No. 333-295051 PROSPECTUS Soluna Holdings, Inc. 1,350,000 Common Warrants 1 to Purchase Up to 1,350,000 Shares of Common Stock 650,000 Common Warrants 2 to Purchase Up to 650,000 Shares of Common Stock 700,000 Pre-Funded Warrants to Purchase Up to 700,000 Shares of Common Stock Up to 2,700,000 Shares of Common Stock Underlying the Common Warrants 1, th

Soluna Announces Fourth Expansion with Blockware, Surpassing 17 MW of Total Capacity New 3.3 MW deployment marks Blockware’s first presence at Project Dorothy 1B

Exhibit 99.1 Soluna Announces Fourth Expansion with Blockware, Surpassing 17 MW of Total Capacity New 3.3 MW deployment marks Blockware’s first presence at Project Dorothy 1B ALBANY, NY, April 21, 2026 – Soluna Holdings, Inc. (“Soluna” or the “Company”) (NASDAQ: SLNH), a developer of green data centers for intensive computing applications, including Bitcoin mining and AI, today announced a new exp

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): April 21, 2026 SOLUNA HOLDINGS, I

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): April 21, 2026 SOLUNA HOLDINGS, INC. (Exact name of Registrant as Specified in Its Charter) Nevada 001-40261 14-1462255 (State or Other Jurisdiction of Incorporation) (Commission File

Up to 26,512,815 Shares of Common Stock

Filed Pursuant to Rule 424(b)(3) Registration No. 333-295052 PROSPECTUS Up to 26,512,815 Shares of Common Stock This prospectus relates to the offer and resale, from time to time, by the selling holder identified in this prospectus (the “Selling Holder”), or its permitted transferees, of up to 26,512,815 shares of common stock, par value $0.001 (“Common Stock”), of Soluna Holdings, Inc., a Nevada

MEMBERSHIP INTERESTS PURCHASE AGREEMENT

Exhibit 10.1 Execution Version MEMBERSHIP INTERESTS PURCHASE AGREEMENT This Membership Interests Purchase Agreement (this “Agreement”) is entered into as of April 15, 2026, by and among Soluna SLC Fund I Projects Holdco LLC, a Delaware limited liability company (the “Seller”), Soluna Digital Inc., a Nevada corporation (the “Purchaser”) and Soluna DVSL JVCo, LLC, a Delaware limited liability compan

SECURITIES PURCHASE AGREEMENT

Exhibit 10.2 SECURITIES PURCHASE AGREEMENT THIS SECURITIES PURCHASE AGREEMENT (this “Agreement”), dated as of April 15, 2026, is between SOLUNA HOLDINGS, INC., a company incorporated under the laws of the State of Nevada (the “Company”), and YA II PN, LTD., a Cayman Islands exempt limited company (the “Investor”). WITNESSETH WHEREAS, the parties desire that, upon the terms and subject to the condi

April 17, 2026

April 17, 2026 VIA EDGAR United States Securities and Exchange Commission Division of Corporation Finance 100 F Street, N.

GUARANTY AGREEMENT

Exhibit 10.3 GUARANTY AGREEMENT This Guaranty (as amended, amended and restated, supplemented or otherwise modified from time to time, this “Guaranty”) is made as of April 15, 2026, by SOLUNA WIND HOLDINGS, INC., a Nevada corporation, and any subsequent party that may join in this Guaranty, the “Guarantors”) in favor of YA II PN, LTD. (“YA II” or the “Creditor”), with respect to all obligations of

COMMON STOCK PURCHASE WARRANT SOLUNA HOLDINGS, INC.

Exhibit 4.2 NEITHER THIS SECURITY NOR THE SECURITIES FOR WHICH THIS SECURITY IS EXERCISABLE HAVE BEEN REGISTERED WITH THE SECURITIES AND EXCHANGE COMMISSION OR THE SECURITIES COMMISSION OF ANY STATE IN RELIANCE UPON AN EXEMPTION FROM REGISTRATION UNDER THE SECURITIES ACT OF 1933, AS AMENDED (THE “SECURITIES ACT”), AND, ACCORDINGLY, MAY NOT BE OFFERED OR SOLD EXCEPT PURSUANT TO AN EFFECTIVE REGISTR

LETTER

April 17, 2026 John Belizaire Chief Executive Officer Soluna Holdings, Inc 325 Washington Ave Extension Albany, New York 12205 Re: Soluna Holdings, Inc Registration Statement on Form S-3 Filed April 15, 2026 File No.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): April 15, 2026 SOLUNA HOLDINGS, I

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): April 15, 2026 SOLUNA HOLDINGS, INC. (Exact name of Registrant as Specified in Its Charter) Nevada 001-40261 14-1462255 (State or Other Jurisdiction of Incorporation) (Commission File

SOLUNA HOLDINGS, INC. Promissory Note

Exhibit 4.1 THIS NOTE HAS NOT BEEN REGISTERED WITH THE SECURITIES AND EXCHANGE COMMISSION OR THE SECURITIES COMMISSION OF ANY STATE. THIS NOTE HAS BEEN SOLD IN RELIANCE UPON AN EXEMPTION FROM REGISTRATION UNDER THE SECURITIES ACT OF 1933, AS AMENDED (THE “SECURITIES ACT”), AND, ACCORDINGLY, MAY NOT BE OFFERED OR SOLD EXCEPT PURSUANT TO AN EFFECTIVE REGISTRATION STATEMENT UNDER THE SECURITIES ACT O

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): April 16, 2026 SOLUNA HOLDINGS, I

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): April 16, 2026 SOLUNA HOLDINGS, INC. (Exact name of Registrant as Specified in Its Charter) Nevada 001-40261 14-1462255 (State or Other Jurisdiction of Incorporation) (Commission File

Soluna Acquires Full Ownership of Project Dorothy 1A, Accelerating Vertical Integration and AI Campus Development $16.5M acquisition consolidates Dorothy campus control; positions Soluna to convert existing infrastructure to AI and market Dorothy 3 t

Exhibit 99.1 Soluna Acquires Full Ownership of Project Dorothy 1A, Accelerating Vertical Integration and AI Campus Development $16.5M acquisition consolidates Dorothy campus control; positions Soluna to convert existing infrastructure to AI and market Dorothy 3 to prospective customers ALBANY, NY, April 16, 2026 – Soluna Holdings, Inc. (“Soluna” or the “Company”) (NASDAQ: SLNH), a developer of gre

EX-99.2

Exhibit 99.2

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): April 10, 2026 SOLUNA HOLDINGS, I

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): April 10, 2026 SOLUNA HOLDINGS, INC. (Exact name of Registrant as Specified in Its Charter) Nevada 001-40261 14-1462255 (State or Other Jurisdiction of Incorporation) (Commission File

As filed with the Securities and Exchange Commission on April 14, 2026

As filed with the Securities and Exchange Commission on April 14, 2026 Registration No.

April 15, 2026

April 15, 2026 VIA EDGAR United States Securities and Exchange Commission Division of Corporation Finance 100 F Street, N.

As filed with the Securities and Exchange Commission on April 14, 2026.

As filed with the Securities and Exchange Commission on April 14, 2026. Registration No. 333- UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM S-1 REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933 SOLUNA HOLDINGS, INC. (Exact name of registrant as specified in its charter) Nevada 7374 14-1462255 (State or other jurisdiction of incorporation or organization) (Prima

Security Type

Calculation of Filing Fee Tables S-1 Soluna Holdings, Inc Table 1: Newly Registered and Carry Forward Securities ☐Not Applicable Security Type Security Class Title Fee Calculation or Carry Forward Rule Amount Registered Proposed Maximum Offering Price Per Unit Maximum Aggregate Offering Price Fee Rate Amount of Registration Fee Carry Forward Form Type Carry Forward File Number Carry Forward Initial Effective Date Filing Fee Previously Paid in Connection with Unsold Securities to be Carried Forward Newly Registered Securities Fees to be Paid 1 Equity Common Stock, par value $0.

Security Type

Calculation of Filing Fee Tables S-3 Soluna Holdings, Inc Table 1: Newly Registered and Carry Forward Securities ☐Not Applicable Security Type Security Class Title Fee Calculation or Carry Forward Rule Amount Registered Proposed Maximum Offering Price Per Unit Maximum Aggregate Offering Price Fee Rate Amount of Registration Fee Carry Forward Form Type Carry Forward File Number Carry Forward Initial Effective Date Filing Fee Previously Paid in Connection with Unsold Securities to be Carried Forward Newly Registered Securities Fees to be Paid 1 Equity Common Stock, par value $0.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): April 9, 2026 SOLUNA HOLDINGS, IN

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): April 9, 2026 SOLUNA HOLDINGS, INC. (Exact name of Registrant as Specified in Its Charter) Nevada 001-40261 14-1462255 (State or Other Jurisdiction of Incorporation) (Commission File

Soluna Announces Monthly Business Update

Exhibit 99.1 Soluna Announces Monthly Business Update ALBANY, NY, April 9, 2026 – Soluna Holdings, Inc. (“Soluna” or the “Company”) (NASDAQ: SLNH), a developer of green data centers for intensive computing applications, including Bitcoin mining and AI, announced its March 2026 project site-level operations, developments, and updates. The Company has provided the following Corporate and Site Update

As filed with the Securities and Exchange Commission on April 7, 2026

As filed with the Securities and Exchange Commission on April 7, 2026 Registration No.

Table 1: Newly Registered Securities

Calculation of Filing Fee Tables S-8 Soluna Holdings, Inc Table 1: Newly Registered Securities Security Type Security Class Title Fee Calculation Rule Amount Registered Proposed Maximum Offering Price Per Unit Maximum Aggregate Offering Price Fee Rate Amount of Registration Fee 1 Equity Common stock, $0.

LETTER

April 7, 2026 John Belizaire Chief Executive Officer Soluna Holdings, Inc 325 Washington Avenue Extension Albany, New York 12205 Re: Soluna Holdings, Inc Draft Registration Statement on Form S-1 Submitted April 1, 2026 CIK No.

COMMON STOCK PURCHASE WARRANT SOLUNA HOLDINGS, INC.

Exhibit 4.3 NEITHER THIS SECURITY NOR THE SECURITIES FOR WHICH THIS SECURITY IS EXERCISABLE HAVE BEEN REGISTERED WITH THE SECURITIES AND EXCHANGE COMMISSION OR THE SECURITIES COMMISSION OF ANY STATE IN RELIANCE UPON AN EXEMPTION FROM REGISTRATION UNDER THE SECURITIES ACT OF 1933, AS AMENDED (THE “SECURITIES ACT”), AND, ACCORDINGLY, MAY NOT BE OFFERED OR SOLD EXCEPT PURSUANT TO AN EFFECTIVE REGISTR

AMENDED AND RESTATED REGISTRATION RIGHTS AGREEMENT

Exhibit 10.3 AMENDED AND RESTATED REGISTRATION RIGHTS AGREEMENT This Amended and Restated Registration Rights Agreement (this “Agreement”) is made and entered into as of April 1, 2026, by and between Soluna Holdings, Inc., a Nevada corporation (together with any successor entity thereto, the “Company”), on the one hand, and Generate Strategic Credit Master Fund I-B, L.P. (the “Warrant Holder”), on

MEMBERSHIP INTEREST PURCHASE AGREEMENT dated as of April 1, 2026, by and among BRISCOE WIND PROJECT HOLDINGS I, LLC, JPM CAPITAL CORPORATION, AND MORGAN STANLEY WIND LLC, AS SELLERS, SOLUNA DV WIND SPONSORCO, LLC, AS BUYER TABLE OF CONTENTS

Exhibit 10.1 Execution Version MEMBERSHIP INTEREST PURCHASE AGREEMENT dated as of April 1, 2026, by and among BRISCOE WIND PROJECT HOLDINGS I, LLC, JPM CAPITAL CORPORATION, AND MORGAN STANLEY WIND LLC, AS SELLERS, AND SOLUNA DV WIND SPONSORCO, LLC, AS BUYER TABLE OF CONTENTS ARTICLE I DEFINITIONS AND REFERENCES 1 Section 1.01 Certain Defined Terms 1 Section 1.02 References and Construction 13 ARTI

COMMON STOCK PURCHASE WARRANT SOLUNA HOLDINGS, INC.

Exhibit 4.2 NEITHER THIS SECURITY NOR THE SECURITIES FOR WHICH THIS SECURITY IS EXERCISABLE HAVE BEEN REGISTERED WITH THE SECURITIES AND EXCHANGE COMMISSION OR THE SECURITIES COMMISSION OF ANY STATE IN RELIANCE UPON AN EXEMPTION FROM REGISTRATION UNDER THE SECURITIES ACT OF 1933, AS AMENDED (THE “SECURITIES ACT”), AND, ACCORDINGLY, MAY NOT BE OFFERED OR SOLD EXCEPT PURSUANT TO AN EFFECTIVE REGISTR

COMMON STOCK PURCHASE WARRANT SOLUNA HOLDINGS, INC.

Exhibit 4.1 NEITHER THIS SECURITY NOR THE SECURITIES FOR WHICH THIS SECURITY IS EXERCISABLE HAVE BEEN REGISTERED WITH THE SECURITIES AND EXCHANGE COMMISSION OR THE SECURITIES COMMISSION OF ANY STATE IN RELIANCE UPON AN EXEMPTION FROM REGISTRATION UNDER THE SECURITIES ACT OF 1933, AS AMENDED (THE “SECURITIES ACT”), AND, ACCORDINGLY, MAY NOT BE OFFERED OR SOLD EXCEPT PURSUANT TO AN EFFECTIVE REGISTR

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): April 1, 2026 SOLUNA HOLDINGS, IN

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): April 1, 2026 SOLUNA HOLDINGS, INC. (Exact name of Registrant as Specified in Its Charter) Nevada 001-40261 14-1462255 (State or Other Jurisdiction of Incorporation) (Commission File

CONSENT AND AMENDMENT NO. 1 TO CREDIT AND GUARANTY AGREEMENT AND AMENDMENT NO. 1 TO PLEDGE AGREEMENT

Exhibit 10.2 Execution Version CONSENT AND AMENDMENT NO. 1 TO CREDIT AND GUARANTY AGREEMENT AND AMENDMENT NO. 1 TO PLEDGE AGREEMENT This Consent and Amendment No. 1 to Credit and Guaranty Agreement and Amendment No. 1 to Pledge Agreement, dated as of April 1, 2026 (this “Amendment”), amends (i) that certain Credit and Guaranty Agreement, dated as of September 12, 2025 (the “Existing Credit Agreeme

Soluna Closes $53M Briscoe Wind Farm Acquisition; Achieves Vertical Integration $6–$11M Year-One Projected EBITDA | 300 MW AI Campus Expansion at Project Dorothy

Exhibit 99.1 Soluna Closes $53M Briscoe Wind Farm Acquisition; Achieves Vertical Integration $6–$11M Year-One Projected EBITDA | 300 MW AI Campus Expansion at Project Dorothy ALBANY, NY, April 2, 2026 — Soluna Holdings, Inc. (“Soluna” or the “Company”) (NASDAQ: SLNH), a developer of green data centers that converts renewable energy into computing power, today announced that it has closed the acqui

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): April 2, 2026 SOLUNA HOLDINGS, IN

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): April 2, 2026 SOLUNA HOLDINGS, INC. (Exact name of Registrant as Specified in Its Charter) Nevada 001-40261 14-1462255 (State or Other Jurisdiction of Incorporation) (Commission File

As confidentially submitted to the Securities and Exchange Commission on April 1, 2026. This draft registration statement has not been filed publicly with the Securities and Exchange Commission and all information herein remains strictly confidential

As confidentially submitted to the Securities and Exchange Commission on April 1, 2026.

Up to $500,000,000 Common Stock

Filed Pursuant to Rule 424(b)(5) Registration No. 333-294152 PROSPECTUS Up to $500,000,000 Common Stock On April 29, 2025, we entered into a certain At the Market Offering Agreement, or Sales Agreement, with H.C. Wainwright & Co., LLC, or Wainwright, relating to shares of our common stock, par value $0.001 per share (“common stock”), offered by this prospectus. In accordance with the terms of the

March 30, 2026

Exhibit 16.1 March 30, 2026 Securities and Exchange Commission 100 F Street, N.E. Washington, DC 20549 Commissioners: We have read Item 4.01 of Form 8-K filed with the U.S. Securities and Exchange Commission on March 30, 2026 of Soluna Holdings, Inc. (the “Company”) and are in agreement with the statements contained in (a) (Dismissal of Independent Registered Public Accounting Firm). We have no ba

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): March 29, 2026 SOLUNA HOLDINGS, I

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): March 29, 2026 SOLUNA HOLDINGS, INC. (Exact name of registrant as specified in its charter) Nevada 001-40261 14-1462255 (State or Other Jurisdiction of Incorporation) (Commission File

Soluna Reports Record 2025 Growth: Pipeline Hits 4.3GW, Raises $142 Million, and Launches AI Infrastructure Strong Capital Formation, Expanded Operations Position Company for an Accelerated 2026 Despite Q4 Hashprice Headwinds

Exhibit 99.1 Soluna Reports Record 2025 Growth: Pipeline Hits 4.3GW, Raises $142 Million, and Launches AI Infrastructure Strong Capital Formation, Expanded Operations Position Company for an Accelerated 2026 Despite Q4 Hashprice Headwinds ALBANY, NY, March 30, 2026 – Soluna Holdings, Inc. (“Soluna Holdings” or the “Company”) (NASDAQ: SLNH), a developer of green data centers for intensive computing

DESCRIPTION OF THE REGISTRANT’S SECURITIES REGISTERED PURSUANT TO SECTION 12 OF THE SECURITIES EXCHANGE ACT OF 1934

Exhibit 4.8 DESCRIPTION OF THE REGISTRANT’S SECURITIES REGISTERED PURSUANT TO SECTION 12 OF THE SECURITIES EXCHANGE ACT OF 1934 Soluna Holdings, Inc., or the Company, we, us or our, has three classes of securities registered under Section 12 of the Securities Exchange Act of 1934, as amended, or the Exchange Act, common stock, $0.001 par value per share, or common stock, 9.0% Series A Cumulative P

STANDBY EQUITY PURCHASE AGREEMENT

STANDBY EQUITY PURCHASE AGREEMENT THIS STANDBY EQUITY PURCHASE AGREEMENT (this “Agreement”) dated as of March 24, 2026 is made by and between YA II PN, LTD.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K x ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2025 OR o TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number: 001-40261 Soluna

Soluna Holdings, Inc. Insider Trading Policy

Soluna Holdings, Inc. Insider Trading Policy For Employees, Associates, Officers and Directors NOVEMBER 6, 2025 I.Introduction, Scope and Purpose of Policy In an effort to protect against prohibited “insider trading” by Soluna Holdings, Inc. (the “Company”) personnel, the Company’s Board of Directors adopted this insider trading policy (the “Policy”) applicable to directors, officers, and associat

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): March 30, 2026 SOLUNA HOLDINGS, I

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): March 30, 2026 SOLUNA HOLDINGS, INC. (Exact name of Registrant as Specified in Its Charter) Nevada 001-40261 14-1462255 (State or Other Jurisdiction of Incorporation) (Commission File

SUBSIDIARIES OF SOLUNA HOLDINGS, INC.

SUBSIDIARIES OF SOLUNA HOLDINGS, INC. Subsidiary Name Jurisdiction of Incorporation or Organization Soluna Callisto Holdings, Inc. Delaware Soluna Digital, Inc. Nevada Soluna Global Services, Inc. Nevada Soluna Cloud, Inc. Nevada Soluna Energy, Inc. Soluna HPC, Inc. Soluna Wind Holdings, Inc. Nevada SUBSIDIARIES OF SOLUNA DIGITAL, INC. Subsidiary Name Jurisdiction of Incorporation or Organization

As filed with the Securities and Exchange Commission on March 30, 2026.

As filed with the Securities and Exchange Commission on March 30, 2026. Registration No. 333-294152 UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 Amendment No. 1 to FORM S-3 REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933 Soluna Holdings, Inc. (Exact name of registrant as specified in its charter) Nevada 14-1462255 (State or Other Jurisdiction of Incorporation or

March 26, 2026

March 26, 2026 VIA EDGAR United States Securities and Exchange Commission Division of Corporation Finance 100 F Street, N.

Soluna Announces Monthly Business Update

Exhibit 99.1 Soluna Announces Monthly Business Update ALBANY, NY, March 10, 2026 – Soluna Holdings, Inc. (“Soluna” or the “Company”) (NASDAQ: SLNH), a developer of green data centers for intensive computing applications, including Bitcoin mining and AI, announced its February 2026 project site-level operations, developments, and updates. The Company has provided the following Corporate and Site Up

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): March 10, 2026 SOLUNA HOLDINGS, I

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): March 10, 2026 SOLUNA HOLDINGS, INC. (Exact name of Registrant as Specified in Its Charter) Nevada 001-40261 14-1462255 (State or Other Jurisdiction of Incorporation) (Commission File

Security Type

Calculation of Filing Fee Tables S-3 Soluna Holdings, Inc Table 1: Newly Registered and Carry Forward Securities ☐Not Applicable Security Type Security Class Title Fee Calculation or Carry Forward Rule Amount Registered Proposed Maximum Offering Price Per Unit Maximum Aggregate Offering Price Fee Rate Amount of Registration Fee Carry Forward Form Type Carry Forward File Number Carry Forward Initial Effective Date Filing Fee Previously Paid in Connection with Unsold Securities to be Carried Forward Newly Registered Securities Equity Common Stock, $0.

As filed with the Securities and Exchange Commission on March 9, 2026.

As filed with the Securities and Exchange Commission on March 9, 2026. Registration No. 333- UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM S-3 REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933 Soluna Holdings, Inc. (Exact name of registrant as specified in its charter) Nevada 14-1462255 (State or Other Jurisdiction of Incorporation or Organization) (I.R.S. Empl

SOLUNA HOLDINGS, INC., as Issuer ●, as Trustee Dated as of ● Subordinated Debt Securities CROSS REFERENCE SHEET 1

Exhibit 4.5 SOLUNA HOLDINGS, INC., as Issuer and ●, as Trustee INDENTURE Dated as of ● Subordinated Debt Securities CROSS REFERENCE SHEET 1 Between Provisions of the Trust Indenture Act of 1939 and the Indenture to be dated as of , 20 between SOLUNA HOLDINGS, INC. and , as Trustee: Section of the Act Section of Indenture 310(a)(1) and (2) 5.08 310(a)(3) and (4) Inapplicable 310(b) 5.09(a), (b) and

SOLUNA HOLDINGS, INC., as Issuer ●, as Trustee Dated as of ● Senior Debt Securities CROSS REFERENCE SHEET 1

Exhibit 4.4 SOLUNA HOLDINGS, INC., as Issuer and ●, as Trustee INDENTURE Dated as of ● Senior Debt Securities CROSS REFERENCE SHEET 1 Between Provisions of the Trust Indenture Act of 1939 and the Indenture to be dated as of , 20 between SOLUNA HOLDINGS, INC. and , as Trustee: Section of the Act Section of Indenture 310(a)(1) and (2) 5.08 310(a)(3) and (4) Inapplicable 310(b) 5.09(a), (b) and (d) 3

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): February 17, 2026 SOLUNA HOLDINGS

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): February 17, 2026 SOLUNA HOLDINGS, INC. (Exact name of Registrant as Specified in Its Charter) Nevada 001-40261 14-1462255 (State or Other Jurisdiction of Incorporation) (Commission F

Soluna Expands Partnership With Blockware, Adding 6 MW at Project Dorothy 1 Deployment began in January and is expected to be completed by the end of February

Exhibit 99.1 Soluna Expands Partnership With Blockware, Adding 6 MW at Project Dorothy 1 Deployment began in January and is expected to be completed by the end of February ALBANY, NY, February 17, 2026 – Soluna Holdings, Inc. (“Soluna” or the “Company”) (NASDAQ: SLNH), a developer of green data centers for intensive computing applications, including Bitcoin mining and AI, today announced the expan

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): February 12, 2026 SOLUNA HOLDINGS

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): February 12, 2026 SOLUNA HOLDINGS, INC. (Exact name of Registrant as Specified in Its Charter) Nevada 001-40261 14-1462255 (State or Other Jurisdiction of Incorporation) (Commission F

Soluna Announces Monthly Business Update Engineering a 350MW AI campus for Project Kati 2

Exhibit 99.1 Soluna Announces Monthly Business Update Engineering a 350MW AI campus for Project Kati 2 ALBANY, NY, February 12, 2026 – Soluna Holdings, Inc. (“Soluna” or the “Company”) (NASDAQ: SLNH), a developer of green data centers for intensive computing applications, including Bitcoin mining and AI, announced its January 2026 project site-level operations, developments, and updates. The Compa

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): February 10, 2026 SOLUNA HOLDINGS

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): February 10, 2026 SOLUNA HOLDINGS, INC. (Exact name of Registrant as Specified in Its Charter) Nevada 001-40261 14-1462255 (State or Other Jurisdiction of Incorporation) (Commission F

Soluna Executes Equipment Supply Agreement with Cormint for 12 MW Kati 1 Deployment Agreement is a blueprint for future deployments across pipeline

Exhibit 99.1 Soluna Executes Equipment Supply Agreement with Cormint for 12 MW Kati 1 Deployment Agreement is a blueprint for future deployments across pipeline ALBANY, NY, February 3, 2026 – Soluna Holdings, Inc. (“Soluna” or the “Company”) (NASDAQ: SLNH), a developer of green data centers for intensive computing applications, including Bitcoin mining and AI, today announced that it has executed

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): February 3, 2026 SOLUNA HOLDINGS,

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): February 3, 2026 SOLUNA HOLDINGS, INC. (Exact name of Registrant as Specified in Its Charter) Nevada 001-40261 14-1462255 (State or Other Jurisdiction of Incorporation) (Commission Fi

Soluna Appoints Michael Picchi as Chief Financial Officer Interim CFO David Michaels to remain on Soluna’s Board following interim period

Exhibit 99.1 Soluna Appoints Michael Picchi as Chief Financial Officer Interim CFO David Michaels to remain on Soluna’s Board following interim period ALBANY, N.Y., Jan. 20, 2026 – Soluna Holdings, Inc. (“Soluna” or the “Company”) (Nasdaq: SLNH), a developer of green data centers for intensive computing applications, including Bitcoin mining and AI, today announced it has appointed Michael Picchi

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): January 19, 2026 SOLUNA HOLDINGS,

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): January 19, 2026 SOLUNA HOLDINGS, INC. (Exact name of Registrant as Specified in Its Charter) Nevada 001-40261 14-1462255 (State or Other Jurisdiction of Incorporation) (Commission Fi

Soluna Holdings, Inc.

Exhibit 10.1 Soluna Holdings, Inc. December 22, 2025 Michael Picchi Via Email Re: Offer of Employment Dear Michael: We are pleased to offer you employment with Soluna Holdings, Inc., a Nevada corporation (the “Company”) on the terms set forth in this letter agreement (together with Exhibit A hereto, the “Letter Agreement”), effective as of March 9, 2026, or such other date as mutually agreed in wr

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): January 15, 2026 SOLUNA HOLDINGS,

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): January 15, 2026 SOLUNA HOLDINGS, INC. (Exact name of Registrant as Specified in Its Charter) Nevada 001-40261 14-1462255 (State or Other Jurisdiction of Incorporation) (Commission Fi

Soluna and Metrobloks to Partner to Unlock 100+ MW of AI and HPC Capacity at Project Kati 2 Co-development model combines secured power, AI-ready design, and rapid deployment for high-density workloads

Exhibit 99.1 Soluna and Metrobloks to Partner to Unlock 100+ MW of AI and HPC Capacity at Project Kati 2 Co-development model combines secured power, AI-ready design, and rapid deployment for high-density workloads ALBANY, NY, January 15, 2026 – Soluna Holdings, Inc. (“Soluna” or the “Company”) (NASDAQ: SLNH), a developer of green data centers for intensive computing applications, including Bitcoi

LETTER

January 15, 2026 John Belizaire Chief Executive Officer Soluna Holdings, Inc. 325 Washington Ave Extension Albany, NY 12205 Re: Soluna Holdings, Inc. Draft Registration Statement on Form S-3 Submitted January 12, 2026 CIK No. 0000064463 Dear John Belizaire: This is to advise you that we do not intend to review your registration statement. We request that you publicly file your registration stateme

Soluna Announces Monthly Business Update

Exhibit 99.1 Soluna Announces Monthly Business Update ALBANY, NY, January 13, 2026 – Soluna Holdings, Inc. (“Soluna” or the “Company”) (NASDAQ: SLNH), a developer of green data centers for intensive computing applications, including Bitcoin mining and AI, announced its December 2025 project site-level operations, developments, and updates. The Company has provided the following Corporate and Site

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): January 13, 2026 SOLUNA HOLDINGS,

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): January 13, 2026 SOLUNA HOLDINGS, INC. (Exact name of Registrant as Specified in Its Charter) Nevada 001-40261 14-1462255 (State or Other Jurisdiction of Incorporation) (Commission Fi

As confidentially submitted to the Securities and Exchange Commission on January 9, 2026. This draft registration statement has not been filed publicly with the Securities and Exchange Commission and all information herein remains strictly confidenti

As confidentially submitted to the Securities and Exchange Commission on January 9, 2026.

SOLUNA HOLDINGS, INC., as Issuer ●, as Trustee Dated as of ● Subordinated Debt Securities CROSS REFERENCE SHEET 1

Exhibit 4.5 SOLUNA HOLDINGS, INC., as Issuer and ●, as Trustee INDENTURE Dated as of ● Subordinated Debt Securities CROSS REFERENCE SHEET 1 Between Provisions of the Trust Indenture Act of 1939 and the Indenture to be dated as of , 20 between SOLUNA HOLDINGS, INC. and , as Trustee: Section of the Act Section of Indenture 310(a)(1) and (2) 5.08 310(a)(3) and (4) Inapplicable 310(b) 5.09(a), (b) and

SOLUNA HOLDINGS, INC., as Issuer ●, as Trustee Dated as of ● Senior Debt Securities CROSS REFERENCE SHEET 1

Exhibit 4.4 SOLUNA HOLDINGS, INC., as Issuer and ●, as Trustee INDENTURE Dated as of ● Senior Debt Securities CROSS REFERENCE SHEET 1 Between Provisions of the Trust Indenture Act of 1939 and the Indenture to be dated as of , 20 between SOLUNA HOLDINGS, INC. and , as Trustee: Section of the Act Section of Indenture 310(a)(1) and (2) 5.08 310(a)(3) and (4) Inapplicable 310(b) 5.09(a), (b) and (d) 3

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): January 8, 2026 SOLUNA HOLDINGS,

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): January 8, 2026 SOLUNA HOLDINGS, INC. (Exact name of Registrant as Specified in Its Charter) Nevada 001-40261 14-1462255 (State or Other Jurisdiction of Incorporation) (Commission Fil

Soluna and Siemens Collaborate to Solve GPU Power Swings in Behind-the-Meter AI Project Grace site will host a 2 MW Texas pilot, developing an innovative approach to a growing problem

Exhibit 99.1 Soluna and Siemens Collaborate to Solve GPU Power Swings in Behind-the-Meter AI Project Grace site will host a 2 MW Texas pilot, developing an innovative approach to a growing problem ALBANY, NY, January 8, 2026 – Soluna Holdings, Inc. (“Soluna” or the “Company”) (NASDAQ: SLNH), a developer of green data centers for intensive computing applications, including Bitcoin mining and AI, to

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): December 9, 2025 SOLUNA HOLDINGS,

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): December 9, 2025 SOLUNA HOLDINGS, INC. (Exact name of Registrant as Specified in Its Charter) Nevada 001-40261 14-1462255 (State or Other Jurisdiction of Incorporation) (Commission Fi

Soluna Announces Monthly Business Update

Exhibit 99.1 Soluna Announces Monthly Business Update ALBANY, NY, December 9, 2025 – Soluna Holdings, Inc. (“Soluna” or the “Company”) (NASDAQ: SLNH), a developer of green data centers for intensive computing applications, including Bitcoin mining and AI, announced its November 2025 project site-level operations, developments, and updates. The Company has provided the following Corporate and Site

Soluna Announces Closing of $32 Million Registered Direct Offering Priced At-The-Market Under Nasdaq Rules

Exhibit 99.1 Soluna Announces Closing of $32 Million Registered Direct Offering Priced At-The-Market Under Nasdaq Rules ALBANY, NY — December 8, 2025 — Soluna Holdings, Inc. (“Soluna” or the “Company”) (NASDAQ: SLNH), a developer of green data centers for intensive computing applications, today announced the closing of its previously announced registered direct offering priced at-the-market under

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): December 8, 2025 SOLUNA HOLDINGS,

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): December 8, 2025 SOLUNA HOLDINGS, INC. (Exact name of Registrant as Specified in Its Charter) Nevada 001-40261 14-1462255 (State or Other Jurisdiction of Incorporation) (Commission Fi

PLACEMENT AGENT COMMON STOCK PURCHASE WARRANT soluna holdings, Inc.

Exhibit 4.3 PLACEMENT AGENT COMMON STOCK PURCHASE WARRANT soluna holdings, Inc. Warrant Shares: Initial Exercise Date: December 5, 2025 THIS PLACEMENT AGENT COMMON STOCK PURCHASE WARRANT (the “Warrant”) certifies that, for value received, or its assigns (the “Holder”) is entitled, upon the terms and subject to the limitations on exercise and the conditions hereinafter set forth, at any time on or

Soluna Announces $32 Million Registered Direct Offering Priced At-The-Market Under Nasdaq Rules

Exhibit 99.1 Soluna Announces $32 Million Registered Direct Offering Priced At-The-Market Under Nasdaq Rules ALBANY, NY — December 5, 2025 — Soluna Holdings, Inc. (“Soluna” or the “Company”) (NASDAQ: SLNH), a developer of green data centers for intensive computing applications, today announced that it has entered into definitive agreements for the purchase and sale of 18,079,144 shares of common s

PRE-FUNDED COMMON STOCK PURCHASE WARRANT soluna holdings, Inc.

Exhibit 4.1 PRE-FUNDED COMMON STOCK PURCHASE WARRANT soluna holdings, Inc. Warrant Shares: Initial Exercise Date: December 5, 2025 THIS PRE-FUNDED COMMON STOCK PURCHASE WARRANT (the “Warrant”) certifies that, for value received, or its assigns (the “Holder”) is entitled, upon the terms and subject to the limitations on exercise and the conditions hereinafter set forth, at any time on or after the

5,929,944 Shares of Common Stock Pre-Funded Warrants to Purchase 12,149,200 Shares of Common Stock Series C Warrants to Purchase 18,079,144 Shares of Common Stock Placement Agent Warrants to Purchase 903,957 Shares of Common Stock 31,132,301 Shares o

Filed Pursuant to Rule 424(b)(5) Registration Statement 333-286638 PROSPECTUS SUPPLEMENT (to Prospectus dated April 29, 2025) 5,929,944 Shares of Common Stock Pre-Funded Warrants to Purchase 12,149,200 Shares of Common Stock Series C Warrants to Purchase 18,079,144 Shares of Common Stock Placement Agent Warrants to Purchase 903,957 Shares of Common Stock 31,132,301 Shares of Common Stock underlying the Pre-Funded Warrants, Series C Warrants and Placement Agent Warrants We are offering to certain investors 5,929,944 shares of our common stock, par value $0.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): December 4, 2025 SOLUNA HOLDINGS,

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): December 4, 2025 SOLUNA HOLDINGS, INC. (Exact name of Registrant as Specified in Its Charter) Nevada 001-40261 14-1462255 (State or Other Jurisdiction of Incorporation) (Commission Fi

SECURITIES PURCHASE AGREEMENT

Exhibit 10.1 SECURITIES PURCHASE AGREEMENT This Securities Purchase Agreement (this “Agreement”) is dated as of December 4, 2025, between Soluna Holdings, Inc., a Nevada corporation (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 s

SERIES C COMMON STOCK PURCHASE WARRANT soluna holdings, Inc.

Exhibit 4.2 SERIES C COMMON STOCK PURCHASE WARRANT soluna holdings, Inc. Warrant Shares: Initial Exercise Date: December , 2025 THIS SERIES C COMMON STOCK PURCHASE WARRANT (the “Warrant”) certifies that, for value received, or its assigns (the “Holder”) is entitled, upon the terms and subject to the limitations on exercise and the conditions hereinafter set forth, at any time on or after the date

CALCULATION OF FILING FEE TABLE Form S-8 (Form Type) Soluna Holdings, Inc. (Exact Name of Registrant as Specified in its Charter) Table 1: Newly Registered Securities Fees Previously Paid

Exhibit 107 CALCULATION OF FILING FEE TABLE Form S-8 (Form Type) Soluna Holdings, Inc.

As filed with the Securities and Exchange Commission on November 21, 2025

As filed with the Securities and Exchange Commission on November 21, 2025 Registration No.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): November 17, 2025 SOLUNA HOLDINGS

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): November 17, 2025 SOLUNA HOLDINGS, INC. (Exact name of Registrant as Specified in Its Charter) Nevada 001-40261 14-1462255 (State or Other Jurisdiction of Incorporation) (Commission F

Soluna Holdings, Inc. Up to 3,500,000 Shares of Common Stock

Filed Pursuant to Rule 424(b)(3) Registration No. 333-291105 PROSPECTUS Soluna Holdings, Inc. Up to 3,500,000 Shares of Common Stock This prospectus relates to the resale of up to 3,500,000 shares of Soluna Holdings, Inc.’s (the “Company,” “we,” “our” or “us”) common stock, par value $0.001 per share (“common stock”), by the selling stockholder listed in this prospectus (the “Selling Stockholder”)

Soluna Reports Q3’25 Results 37% Increase in Revenue Sequentially, Gross Profit Increased to 28%, Cash Swells to a Record $60 Million

Exhibit 99.1 Soluna Reports Q3’25 Results 37% Increase in Revenue Sequentially, Gross Profit Increased to 28%, Cash Swells to a Record $60 Million ALBANY, NY, November 17, 2025 - Soluna Holdings, Inc. (“Soluna” or the “Company”) (NASDAQ: SLNH), a developer of green data centers for intensive computing applications, including Bitcoin mining and AI, announced its financial results for the third quar

EX-99.2

Exhibit 99.2

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended September 30, 2025 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number: 001-40261 Soluna Holdings,

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): November 13, 2025 SOLUNA HOLDINGS

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): November 13, 2025 SOLUNA HOLDINGS, INC. (Exact name of Registrant as Specified in Its Charter) Nevada 001-40261 14-1462255 (State or Other Jurisdiction of Incorporation) (Commission F

Soluna Completes Project Dorothy 2, Increasing Operational Capacity by 64% to 123 MW The 98 MW site achieves over 3.9 EH/s of sustainable compute with 95% uptime and industry-leading efficiency

Exhibit 99.1 Soluna Completes Project Dorothy 2, Increasing Operational Capacity by 64% to 123 MW The 98 MW site achieves over 3.9 EH/s of sustainable compute with 95% uptime and industry-leading efficiency ALBANY, NY — November 13, 2025— Soluna Holdings, Inc. (“Soluna” or the “Company”) (NASDAQ: SLNH), a developer of green data centers for intensive computing applications, today announced the com

Soluna Holdings, Inc. 2,000,000 Common Warrants to Purchase Up to 2,000,000 Shares of Common Stock 2,000,000 Pre-Funded Warrants to Purchase Up to 2,000,000 Shares of Common Stock Up to 4,000,000 Shares of Common Stock Underlying the Common Warrants

Filed Pursuant to Rule 424(b)(3) Registration No. 333-290546 PROSPECTUS Soluna Holdings, Inc. 2,000,000 Common Warrants to Purchase Up to 2,000,000 Shares of Common Stock 2,000,000 Pre-Funded Warrants to Purchase Up to 2,000,000 Shares of Common Stock Up to 4,000,000 Shares of Common Stock Underlying the Common Warrants and the Pre-Funded Warrants This prospectus relates to the resale of (i) 2,000

EX-3.1

Exhibit 3.1

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): November 7, 2025 SOLUNA HOLDINGS,

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): November 7, 2025 SOLUNA HOLDINGS, INC. (Exact name of Registrant as Specified in Its Charter) Nevada 001-40261 14-1462255 (State or Other Jurisdiction of Incorporation) (Commission Fi

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): November 6, 2025 SOLUNA HOLDINGS,

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): November 6, 2025 SOLUNA HOLDINGS, INC. (Exact name of Registrant as Specified in Its Charter) Nevada 001-40261 14-1462255 (State or Other Jurisdiction of Incorporation) (Commission Fi

Soluna Announces Monthly Business Update Dorothy 2 Phase 3 Completed, Kati-2 AI Development Begins, Expands Board

Exhibit 99.1 Soluna Announces Monthly Business Update Dorothy 2 Phase 3 Completed, Kati-2 AI Development Begins, Expands Board ALBANY, NY, November 6, 2025 – Soluna Holdings, Inc. (“Soluna” or the “Company”) (NASDAQ: SLNH), a developer of green data centers for intensive computing applications, including Bitcoin mining and AI, announced its October 2025 project site-level operations, developments,

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. )

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. ) Filed by the Registrant ☒ Filed by a party other than the Registrant ☐ Check the appropriate box: ☐ Preliminary Proxy Statement ☐ Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)(2)) ☐ Defin

Calculation of Filing Fee Tables Form S-1 (Form Type) Soluna Holdings, Inc. (Exact Name of Registrant as Specified in its Charter) Table 1: Newly Registered Securities Fees Previously Paid

Exhibit 107 Calculation of Filing Fee Tables Form S-1 (Form Type) Soluna Holdings, Inc.

As filed with the Securities and Exchange Commission on October 27, 2025

As filed with the Securities and Exchange Commission on October 27, 2025 Registration No.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): October 15, 2025 SOLUNA HOLDINGS,

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): October 15, 2025 SOLUNA HOLDINGS, INC. (Exact name of Registrant as Specified in Its Charter) Nevada 001-40261 14-1462255 (State or Other Jurisdiction of Incorporation) (Commission Fi

Ask Me Anything (AMA): Answering Investors’ Recently Asked Questions

Exhibit 99.2 Ask Me Anything (AMA): Answering Investors’ Recently Asked Questions Welcome to another installment of Soluna’s AMA (Ask Me Anything) series, where you — our readers and our followers on Twitter and LinkedIn — can get your questions answered. In this Q&A, John Belizaire, CEO of Soluna, answers shareholders’ and potential investors’ most-asked questions. Learn how to submit your questi

Soluna Appoints Agnes Budzyn to Board of Directors Former BlackRock and ConsenSys executive adds deep expertise in finance, digital assets, and technology

Exhibit 99.1 Soluna Appoints Agnes Budzyn to Board of Directors Former BlackRock and ConsenSys executive adds deep expertise in finance, digital assets, and technology ALBANY, NY — October 21, 2025 — Soluna Holdings, Inc. (“Soluna” or the “Company”) (NASDAQ: SLNH), a developer of green data centers for intensive computing applications, today announced the appointment of Agnes Budzyn to its Board o

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. )

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. ) Filed by the Registrant ☒ Filed by a party other than the Registrant ☐ Check the appropriate box: ☐ Preliminary Proxy Statement ☐ Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)(2)) ☐ Defin

As filed with the Securities and Exchange Commission on October 16, 2025

As filed with the Securities and Exchange Commission on October 16, 2025 Registration No.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. )

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. ) Filed by the Registrant ☒ Filed by a party other than the Registrant ☐ Check the appropriate box: ☐ Preliminary Proxy Statement ☐ Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)(2)) ☒ Defin

Soluna and KULR Technology Group Announce 3.3 MW Hosting Partnership at Project Sophie Soluna’s first treasury-focused partnership signals a broadening customer base

Exhibit 99.1 Soluna and KULR Technology Group Announce 3.3 MW Hosting Partnership at Project Sophie Soluna’s first treasury-focused partnership signals a broadening customer base ALBANY, NY — October, 9, 2025— Soluna Holdings, Inc. (“Soluna” or the “Company”) (NASDAQ: SLNH), a developer of green data centers for intensive computing applications, today announced a new hosting partnership with KULR

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): October 9, 2025 SOLUNA HOLDINGS,

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): October 9, 2025 SOLUNA HOLDINGS, INC. (Exact name of Registrant as Specified in Its Charter) Nevada 001-40261 14-1462255 (State or Other Jurisdiction of Incorporation) (Commission Fil

Soluna Announces Monthly Business Update Settles with NYDIG, Nears Dorothy 2 Completion, Secures $100 Million Facility, and Breaks Ground on Project Kati

Exhibit 99.1 Soluna Announces Monthly Business Update Settles with NYDIG, Nears Dorothy 2 Completion, Secures $100 Million Facility, and Breaks Ground on Project Kati ALBANY, NY, October 7, 2025 – Soluna Holdings, Inc. (“Soluna” or the “Company”) (NASDAQ: SLNH), a developer of green data centers for intensive computing applications, including Bitcoin mining and AI, announced its September 2025 pro

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): October 7, 2025 SOLUNA HOLDINGS,

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): October 7, 2025 SOLUNA HOLDINGS, INC. (Exact name of Registrant as Specified in Its Charter) Nevada 001-40261 14-1462255 (State or Other Jurisdiction of Incorporation) (Commission Fil

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): October 3, 2025 SOLUNA HOLDINGS,

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): October 3, 2025 SOLUNA HOLDINGS, INC. (Exact name of Registrant as Specified in Its Charter) Nevada 001-40261 14-1462255 (State or Other Jurisdiction of Incorporation) (Commission Fil

Soluna Regains Compliance with Nasdaq Listing Requirements

Exhibit 99.1 Soluna Regains Compliance with Nasdaq Listing Requirements ALBANY, NY, October 6, 2025 – Soluna Holdings, Inc. (“Soluna” or the “Company”) (NASDAQ: SLNH), a developer of green data centers for intensive computing applications such as AI and Bitcoin mining, today announced that it has received notice from The Nasdaq Stock Market LLC (“Nasdaq”) that the Company has regained compliance w

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. )

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. ) Filed by the Registrant ☒ Filed by a party other than the Registrant ☐ Check the appropriate box: ☒ Preliminary Proxy Statement ☐ Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)(2)) ☐ Defin

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): September 29, 2025 SOLUNA HOLDING

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): September 29, 2025 SOLUNA HOLDINGS, INC. (Exact name of Registrant as Specified in Its Charter) Nevada 001-40261 14-1462255 (State or Other Jurisdiction of Incorporation) (Commission

Soluna and Canaan Inc. Partner to Deploy 20 MW of Next-Gen Bitcoin Miners at Wind-Powered Data Center in Texas Strategic Deal Advances Soluna’s Texas Expansion and Supports Canaan’s North American Mining Growth

Exhibit 99.1 Soluna and Canaan Inc. Partner to Deploy 20 MW of Next-Gen Bitcoin Miners at Wind-Powered Data Center in Texas Strategic Deal Advances Soluna’s Texas Expansion and Supports Canaan’s North American Mining Growth Albany, New York and Singapore — September 30, 2025 — Soluna Holdings, Inc. (“Soluna” or the “Company”) (NASDAQ: SLNH), a developer of green data centers for intensive computin

LETTER

September 29, 2025 John Belizaire Chief Executive Officer Soluna Holdings, Inc 325 Washington Ave Extension Albany, NY 12205 Re: Soluna Holdings, Inc Registration Statement on Form S-3 Filed September 26, 2025 File No.

As filed with the Securities and Exchange Commission on September 26, 2025

As filed with the Securities and Exchange Commission on September 26, 2025 Registration No.

Calculation of Filing Fee Tables Form S-3 (Form Type) Soluna Holdings, Inc. (Exact Name of Registrant as Specified in its Charter) Fees Previously Paid Table 1: Newly Registered Securities

Exhibit 107 Calculation of Filing Fee Tables Form S-3 (Form Type) Soluna Holdings, Inc.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): September 23, 2025 SOLUNA HOLDING

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): September 23, 2025 SOLUNA HOLDINGS, INC. (Exact name of Registrant as Specified in Its Charter) Nevada 001-40261 14-1462255 (State or Other Jurisdiction of Incorporation) (Commission

Up to $87,650,000 Common Stock

PROSPECTUS SUPPLEMENT (To Prospectus dated April 29, 2025) Filed Pursuant to Rule 424(b)(5) Registration No.

Soluna Secures $100M Facility from Generate Capital to Expand Green Data Centers Strategic partnership to accelerate deployment of clean computing infrastructure for AI

Exhibit 99.1 Soluna Secures $100M Facility from Generate Capital to Expand Green Data Centers Strategic partnership to accelerate deployment of clean computing infrastructure for AI ALBANY, NY, September 16, 2025 – Soluna Holdings, Inc. (“Soluna” or the “Company”), (NASDAQ: SLNH), a developer of green data centers for intensive computing applications, including AI and Bitcoin mining, today announc

COMMON STOCK PURCHASE WARRANT SOLUNA HOLDINGS, INC.

Exhibit 4.2 NEITHER THIS SECURITY NOR THE SECURITIES FOR WHICH THIS SECURITY IS EXERCISABLE HAVE BEEN REGISTERED WITH THE SECURITIES AND EXCHANGE COMMISSION OR THE SECURITIES COMMISSION OF ANY STATE IN RELIANCE UPON AN EXEMPTION FROM REGISTRATION UNDER THE SECURITIES ACT OF 1933, AS AMENDED (THE “SECURITIES ACT”), AND, ACCORDINGLY, MAY NOT BE OFFERED OR SOLD EXCEPT PURSUANT TO AN EFFECTIVE REGISTR

Soluna Holdings, Inc.

Exhibit 10.3 Execution Version Soluna Holdings, Inc. September 12, 2025 Generate Strategic Credit Master Fund I-A, L.P. c/o Generate Capital, PBC 560 Davis St, Suite 250 San Francisco, CA 94111 Re: Board Observation Rights Ladies and Gentlemen: Reference is made to that certain Credit and Guaranty Agreement, dated as of the date hereof (as amended, restated, supplemented, or otherwise amended from

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): September 12, 2025 SOLUNA HOLDING

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): September 12, 2025 SOLUNA HOLDINGS, INC. (Exact name of Registrant as Specified in Its Charter) Nevada 001-40261 14-1462255 (State or Other Jurisdiction of Incorporation) (Commission

CREDIT AND GUARANTY AGREEMENT by and among Soluna DVSL ComputeCo, LLC, a Delaware limited liability company, Soluna DVSL II ComputeCo, LLC, a Delaware limited liability company, Soluna KK I ComputeCo LLC, a Delaware limited liability company, as Borr

Exhibit 10.1 CERTAIN IDENTIFIED INFORMATION HAS BEEN EXCLUDED FROM THIS EXHIBIT BECAUSE IT IS NOT MATERIAL AND IS THE TYPE OF INFORMATION THAT THE REGISTRANT CUSTOMARILY AND ACTUALLY TREATS AS PRIVATE AND CONFIDENTIAL. REDACTED INFORMATION IS INDICATED BY [***] Execution Version THE TRANCHE A-1 LOANS AND THE TRANCHE A-3 LOANS ISSUED UNDER THIS AGREEMENT ARE BEING ISSUED AND, UPON ISSUANCE, THE TRA

REGISTRATION RIGHTS AGREEMENT

Exhibit 10.2 REGISTRATION RIGHTS AGREEMENT This Registration Rights Agreement (this “Agreement”) is made and entered into as of September 12, 2025, by and between Soluna Holdings, Inc., a Nevada corporation (together with any successor entity thereto, the “Company”), on the one hand, and Generate Strategic Credit Master Fund I-B, L.P. (the “Warrant Holder”), on the other hand. WHEREAS, in connecti

COMMON STOCK PURCHASE WARRANT SOLUNA HOLDINGS, INC.

Exhibit 4.1 NEITHER THIS SECURITY NOR THE SECURITIES FOR WHICH THIS SECURITY IS EXERCISABLE HAVE BEEN REGISTERED WITH THE SECURITIES AND EXCHANGE COMMISSION OR THE SECURITIES COMMISSION OF ANY STATE IN RELIANCE UPON AN EXEMPTION FROM REGISTRATION UNDER THE SECURITIES ACT OF 1933, AS AMENDED (THE “SECURITIES ACT”), AND, ACCORDINGLY, MAY NOT BE OFFERED OR SOLD EXCEPT PURSUANT TO AN EFFECTIVE REGISTR

Soluna Breaks Ground on its Largest Site to Date, Project Kati Texas wind-powered facility is expected to deliver 166 MW of clean computing for AI and Bitcoin

Exhibit 99.1 Soluna Breaks Ground on its Largest Site to Date, Project Kati Texas wind-powered facility is expected to deliver 166 MW of clean computing for AI and Bitcoin ALBANY, NY, September 11, 2025 – Soluna Holdings, Inc. (“Soluna” or the “Company”) (NASDAQ: SLNH), a developer of green data centers for intensive computing applications, including AI and Bitcoin mining, today announced the sche

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): September 11, 2025 SOLUNA HOLDING

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): September 11, 2025 SOLUNA HOLDINGS, INC. (Exact name of Registrant as Specified in Its Charter) Nevada 001-40261 14-1462255 (State or Other Jurisdiction of Incorporation) (Commission

Soluna Announces Monthly Business Update Surpasses 1 Gigawatt Milestone and Starts Project Kati 1 Construction

Exhibit 99.1 Soluna Announces Monthly Business Update Surpasses 1 Gigawatt Milestone and Starts Project Kati 1 Construction ALBANY, NY, September 9, 2025 – Soluna Holdings, Inc. (“Soluna” or the “Company”) (NASDAQ: SLNH), a developer of green data centers for intensive computing applications, including Bitcoin mining and AI, announced its August 2025 project site-level operations, developments, an

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): September 9, 2025 SOLUNA HOLDINGS

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): September 9, 2025 SOLUNA HOLDINGS, INC. (Exact name of Registrant as Specified in Its Charter) Nevada 001-40261 14-1462255 (State or Other Jurisdiction of Incorporation) (Commission F

Up to $8,585,280 Common Stock

PROSPECTUS SUPPLEMENT (To Prospectus dated April 29, 2025) Filed Pursuant to Rule 424(b)(5) Registration No.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): August 26, 2025 SOLUNA HOLDINGS,

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): August 26, 2025 SOLUNA HOLDINGS, INC. (Exact name of Registrant as Specified in Its Charter) Nevada 001-40261 14-1462255 (State or Other Jurisdiction of Incorporation) (Commission Fil

Soluna Surpasses One Gigawatt of Clean Computing Projects with Launch of Two New Sites Projects Gladys and Fei highlight the company’s diversification into solar and expansion of wind-powered data centers

Exhibit 99.1 Soluna Surpasses One Gigawatt of Clean Computing Projects with Launch of Two New Sites Projects Gladys and Fei highlight the company’s diversification into solar and expansion of wind-powered data centers ALBANY, NY, August 26, 2025 – Soluna Holdings, Inc. (“Soluna” or the “Company”), (NASDAQ: SLNH), a developer of green data centers for intensive computing applications, including Bit

As filed with the Securities and Exchange Commission on August 22, 2025

As filed with the Securities and Exchange Commission on August 22, 2025 Registration No.

CALCULATION OF FILING FEE TABLE Form S-8 (Form Type) Soluna Holdings, Inc. (Exact Name of Registrant as Specified in its Charter) Table 1: Newly Registered Securities Fees Previously Paid

Exhibit 107 CALCULATION OF FILING FEE TABLE Form S-8 (Form Type) Soluna Holdings, Inc.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): August 18, 2025 SOLUNA HOLDINGS,

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): August 18, 2025 SOLUNA HOLDINGS, INC. (Exact name of Registrant as Specified in Its Charter) Nevada 001-40261 14-1462255 (State or Other Jurisdiction of Incorporation) (Commission Fil

Soluna Reports Q2’25 Results Steady gross margin, continued improvement in Three Month Adjusted EBITDA of +$2.3 million since Q3 2024, and energized Dorothy 2

Exhibit 99.1 Soluna Reports Q2’25 Results Steady gross margin, continued improvement in Three Month Adjusted EBITDA of +$2.3 million since Q3 2024, and energized Dorothy 2 ALBANY, NY, August 15, 2025 - Soluna Holdings, Inc. (“Soluna” or the “Company”) (NASDAQ: SLNH), a developer of green data centers for intensive computing applications, including Bitcoin mining and AI, announced its financial res

EX-99.2

Exhibit 99.2

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): August 15, 2025 SOLUNA HOLDINGS,

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): August 15, 2025 SOLUNA HOLDINGS, INC. (Exact name of Registrant as Specified in Its Charter) Nevada 001-40261 14-1462255 (State or Other Jurisdiction of Incorporation) (Commission Fil

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended June 30, 2025 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number: 001-40261 Soluna Holdings, Inc.

Soluna Expands Partnership with Galaxy Digital to Deploy 48 MW at Project Kati New deployment— largest to date—secures its first operational partner at Project Kati 1, expands to 83 MW, and is construction-ready to launch.

Exhibit 99.1 Soluna Expands Partnership with Galaxy Digital to Deploy 48 MW at Project Kati New deployment— largest to date—secures its first operational partner at Project Kati 1, expands to 83 MW, and is construction-ready to launch. ALBANY, NY, August 12, 2025 – Soluna Holdings, Inc. (“Soluna” or the “Company”), (NASDAQ: SLNH), a developer of green data centers for intensive computing applicati

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): August 12, 2025 SOLUNA HOLDINGS,

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): August 12, 2025 SOLUNA HOLDINGS, INC. (Exact name of Registrant as Specified in Its Charter) Nevada 001-40261 14-1462255 (State or Other Jurisdiction of Incorporation) (Commission Fil

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): August 5, 2025 SOLUNA HOLDINGS, I

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): August 5, 2025 SOLUNA HOLDINGS, INC. (Exact name of Registrant as Specified in Its Charter) Nevada 001-40261 14-1462255 (State or Other Jurisdiction of Incorporation) (Commission File

Consulting Agreement, entered into on August 8, 2025 and effective August 21, 2025, between Soluna Holdings, Inc. and David Michaels

Exhibit 10.1 CFO CONSULTING AGREEMENT CFO CONSULTING AGREEMENT dated as of August 21, 2025 (“Agreement”), between Soluna Holdings, Inc., a Nevada corporation (the “Company”), and David Michaels (“Consultant”). WHEREAS, the Board of Directors of the Company desires to engage Consultant to provide consulting services, upon the terms and subject to the conditions hereinafter set forth; and WHEREAS, t

Soluna Holdings Announces CFO Transition David Michaels, member of the board, will serve as interim CFO

Exhibit 99.1 Soluna Holdings Announces CFO Transition David Michaels, member of the board, will serve as interim CFO ALBANY, NY, August 8, 2025 – Soluna Holdings, Inc. (“Soluna” or the “Company”), (NASDAQ: SLNH), a developer of green data centers for intensive computing applications, including Bitcoin mining and AI, today announced that it has accepted the resignation of its Chief Financial Office

Earnings Power Presentation, dated August 7, 2025

Exhibit 99.2

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): August 7, 2025 SOLUNA HOLDINGS, I

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): August 7, 2025 SOLUNA HOLDINGS, INC. (Exact name of Registrant as Specified in Its Charter) Nevada 001-40261 14-1462255 (State or Other Jurisdiction of Incorporation) (Commission File

Soluna Announces Monthly Business Update Project Dorothy 2 completes Phase 2 construction and begins customer ramp-up; Project Kati prepares for groundbreaking

Exhibit 99.1 Soluna Announces Monthly Business Update Project Dorothy 2 completes Phase 2 construction and begins customer ramp-up; Project Kati prepares for groundbreaking ALBANY, NY, August 7, 2025 – Soluna Holdings, Inc. (“Soluna” or the “Company”), (NASDAQ: SLNH), a developer of green data centers for intensive computing applications, including Bitcoin mining and AI, announced its July 2025 pr

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): August 6, 2025 SOLUNA HOLDINGS, I

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): August 6, 2025 SOLUNA HOLDINGS, INC. (Exact name of Registrant as Specified in Its Charter) Nevada 001-40261 14-1462255 (State or Other Jurisdiction of Incorporation) (Commission File

Ask Me Anything (AMA): Answering Investors’ Recently Asked Questions

Exhibit 99.1 Ask Me Anything (AMA): Answering Investors’ Recently Asked Questions Welcome to another installment of Soluna’s AMA (Ask Me Anything) series, where you — our readers and our followers on Twitter and LinkedIn — can get your questions answered. In this Q&A, John Belizaire, CEO of Soluna, answers shareholders’ and potential investors’ most-asked questions. Learn how to submit your questi

Regulation FD Disclosure, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): July 22, 2025 SOLUNA HOLDINGS, INC. (Exact name of Registrant as Specified in Its Charter) Nevada 001-40261 14-1462255 (State or Other Jurisdiction of Incorporation) (Commission File

Soluna Closes $20M Funding from Spring Lane Capital to Begin Construction on Project Kati 1 This investment follows previous funding from SLC at Soluna’s flagship project site

Exhibit 99.1 Soluna Closes $20M Funding from Spring Lane Capital to Begin Construction on Project Kati 1 This investment follows previous funding from SLC at Soluna’s flagship project site ALBANY, NY, July 22, 2025 – Soluna Holdings, Inc. (“Soluna” or the “Company”), (NASDAQ: SLNH), a developer of green data centers for intensive computing applications, including Bitcoin mining and AI, today annou

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. )

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. ) Filed by the Registrant ☒ Filed by a party other than the Registrant ☐ Check the appropriate box: ☐ Preliminary Proxy Statement ☐ Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)

ARS

Soluna Holdings, Inc. Ticker Symbol: SLNH 2024 Annual Report2024 was a defining year for Soluna. We grew revenue by more than 80%, reached $38 million, and achieved positive cash flow from our Bitcoin Hosting business — proof that our model is working. We brought Project Dorothy 1A and 1B into full-year operation and launched our Demand Response Services (DRS), generating $2.1 million in new reven

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): July 15, 2025 SOLUNA HOLDINGS, IN

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): July 15, 2025 SOLUNA HOLDINGS, INC. (Exact name of Registrant as Specified in Its Charter) Nevada 001-40261 14-1462255 (State or Other Jurisdiction of Incorporation) (Commission File

Form of Pre-Funded Warrant issued in the Offering.

Exhibit 4.3 PRE-FUNDED COMMON STOCK PURCHASE WARRANT soluna holdings, Inc. Warrant Shares: Initial Exercise Date: July 17, 2025 THIS PRE-FUNDED COMMON STOCK PURCHASE WARRANT (the “Warrant”) certifies that, for value received, or its assigns (the “Holder”) is entitled, upon the terms and subject to the limitations on exercise and the conditions hereinafter set forth, at any time on or after the dat

Form of Series A Warrant issued in the Offering.

Exhibit 4.1 SERIES A COMMON STOCK PURCHASE WARRANT soluna holdings, Inc. Warrant Shares: Issue Date: July 17, 2025 THIS SERIES A COMMON STOCK PURCHASE WARRANT (the “Warrant”) certifies that, for value received, or its assigns (the “Holder”) is entitled, upon the terms and subject to the limitations on exercise and the conditions hereinafter set forth, at any time on or after the date hereof (the “

Soluna Holdings, Inc. Announces Closing of $5 Million Public Offering

Exhibit 99.2 Soluna Holdings, Inc. Announces Closing of $5 Million Public Offering ALBANY, NY, July 17, 2025 – Soluna Holdings, Inc. (“Soluna” or the “Company”) (NASDAQ: SLNH), a developer of green data centers for intensive computing applications including Bitcoin mining and Artificial Intelligence (AI), today announced the closing of its previously announced public offering of an aggregate of 9,

Form of Series B Warrant issued in the Offering.

Exhibit 4.2 SERIES B COMMON STOCK PURCHASE WARRANT soluna holdings, Inc. Warrant Shares: Issue Date: July 17, 2025 THIS SERIES B COMMON STOCK PURCHASE WARRANT (the “Warrant”) certifies that, for value received, or its assigns (the “Holder”) is entitled, upon the terms and subject to the limitations on exercise and the conditions hereinafter set forth, at any time on or after the date hereof (the “

Soluna Holdings, Inc. Announces Pricing of $5 Million Public Offering

Exhibit 99.1 Soluna Holdings, Inc. Announces Pricing of $5 Million Public Offering ALBANY, NY, July 15, 2025 – Soluna Holdings, Inc. (“Soluna” or the “Company”) (NASDAQ: SLNH), a developer of green data centers for intensive computing applications including Bitcoin mining and Artificial Intelligence (AI), today announced the pricing of a public offering of an aggregate of 9,090,909 shares of its c

Form of Placement Agent Warrant issued in the Offering.

Exhibit 4.4 PLACEMENT AGENT COMMON STOCK PURCHASE WARRANT soluna holdings, Inc. Warrant Shares: Issue Date: July 17, 2025 THIS PLACEMENT AGENT COMMON STOCK PURCHASE WARRANT (the “Warrant”) certifies that, for value received, or its assigns (the “Holder”) is entitled, upon the terms and subject to the limitations on exercise and the conditions hereinafter set forth, at any time on or after the date

8,794,544 Shares of Common Stock Pre-Funded Warrants to Purchase 296,365 Shares of Common Stock Series A Warrants to Purchase 9,090,909 Shares of Common Stock Series B Warrants to Purchase 9,090,909 Shares of Common Stock Placement Agent Warrants to

Filed Pursuant to Rule 424(b)(4) Registration Statement 333-287519 PROSPECTUS 8,794,544 Shares of Common Stock Pre-Funded Warrants to Purchase 296,365 Shares of Common Stock Series A Warrants to Purchase 9,090,909 Shares of Common Stock Series B Warrants to Purchase 9,090,909 Shares of Common Stock Placement Agent Warrants to Purchase 454,545 Shares of Common Stock 18,932,728 Shares of Common Stock underlying Pre-Funded Warrants, Series A Warrants, Series B Warrants and Placement Agent Warrants We are offering 8,794,544 shares of our common stock, par value $0.

Regulation FD Disclosure, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): July 14, 2025 SOLUNA HOLDINGS, INC. (Exact name of Registrant as Specified in Its Charter) Nevada 001-40261 14-1462255 (State or Other Jurisdiction of Incorporation) (Commission File

Investor Presentation, July 2025

Exhibit 99.2

Soluna Holdings’ CEO John Belizaire Shares Vision for Scalable Renewable Computing in 2025 Shareholder Letter

Exhibit 99.1 Soluna Holdings’ CEO John Belizaire Shares Vision for Scalable Renewable Computing in 2025 Shareholder Letter Albany, NY – July 14, 2025 — Soluna Holdings, Inc. (“Soluna” or the “Company”) (NASDAQ: SLNH), a developer of green data centers for intensive computing applications, including Bitcoin mining and AI, today announced an open letter to shareholders from CEO John Belizaire. A lon

As filed with the Securities and Exchange Commission on July 11, 2025

As filed with the Securities and Exchange Commission on July 11, 2025 Registration No.

Regulation FD Disclosure, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): July 10, 2025 SOLUNA HOLDINGS, INC. (Exact name of Registrant as Specified in Its Charter) Nevada 001-40261 14-1462255 (State or Other Jurisdiction of Incorporation) (Commission File

Soluna Announces Monthly Business Update Expansions at Dorothy 2, and Long Term Power Pipeline Swells to 2.8 GW

Exhibit 99.1 Soluna Announces Monthly Business Update Expansions at Dorothy 2, and Long Term Power Pipeline Swells to 2.8 GW ALBANY, NY, July 10, 2025 – Soluna Holdings, Inc. (“Soluna” or the “Company”), (NASDAQ: SLNH), a developer of green data centers for intensive computing applications, including Bitcoin mining and AI, announced its June 2025 project site-level operations, developments, and up

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. )

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. ) Filed by the Registrant ☒ Filed by a party other than the Registrant ☐ Check the appropriate box: ☒ Preliminary Proxy Statement ☐ Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)

Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): July 8, 2025 SOLUNA HOLDINGS, INC. (Exact name of Registrant as Specified in Its Charter) Nevada 001-40261 14-1462255 (State or Other Jurisdiction of Incorporation) (Commission File N

Regulation FD Disclosure, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): July 8, 2025 SOLUNA HOLDINGS, INC. (Exact name of Registrant as Specified in Its Charter) Nevada 001-40261 14-1462255 (State or Other Jurisdiction of Incorporation) (Commission File N

Soluna Fills Rack Capacity at Dorothy 2 with 30 MW Expansion with Top-Tier Bitcoin

Exhibit 99.1 Soluna Fills Rack Capacity at Dorothy 2 with 30 MW Expansion with Top-Tier Bitcoin Miner ALBANY, NY, July 8, 2025 – Soluna Holdings, Inc. (“Soluna” or the “Company”), (NASDAQ: SLNH), a developer of green data centers for intensive computing applications, including Bitcoin mining and AI, today announced a 30 MW expansion with an industry-leading Bitcoin miner at the company’s flagship

Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): July 3, 2025 SOLUNA HOLDINGS, INC. (Exact name of Registrant as Specified in Its Charter) Nevada 001-40261 14-1462255 (State or Other Jurisdiction of Incorporation) (Commission File N

Soluna Expands Long-Term Partnership with Compass Mining Expands into Project Dorothy 2, Totaling 13 MW

Exhibit 99.1 Soluna Expands Long-Term Partnership with Compass Mining Expands into Project Dorothy 2, Totaling 13 MW ALBANY, NY, June 24, 2025 – Soluna Holdings, Inc. (“Soluna” or the “Company”), (NASDAQ: SLNH), a developer of green data centers for intensive computing applications, including Bitcoin mining and AI, today announced the renewal and expansion of its long-standing partnership with Com

Regulation FD Disclosure, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): June 24, 2025 SOLUNA HOLDINGS, INC. (Exact name of Registrant as Specified in Its Charter) Nevada 001-40261 14-1462255 (State or Other Jurisdiction of Incorporation) (Commission File

Regulation FD Disclosure, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): June 18, 2025 SOLUNA HOLDINGS, INC. (Exact name of Registrant as Specified in Its Charter) Nevada 001-40261 14-1462255 (State or Other Jurisdiction of Incorporation) (Commission File

Soluna Expands Partnership with Blockware by Over 50% at Project Dorothy 2 Now Totaling 8 MW of Sustainable Hosting Capacity

Exhibit 99.1 Soluna Expands Partnership with Blockware by Over 50% at Project Dorothy 2 Now Totaling 8 MW of Sustainable Hosting Capacity ALBANY, NY, June 18, 2025 – Soluna Holdings, Inc. (“Soluna” or the “Company”), (NASDAQ: SLNH), a developer of green data centers for intensive computing applications, including Bitcoin mining and AI, today announced that it has signed a hosting expansion agreeme

Form of Series B Warrant issued in this Offering.

Exhibit 4.26 EXHIBIT C-2 SERIES B COMMON STOCK PURCHASE WARRANT soluna holdings, Inc. Warrant Shares: Issue Date: , 2025 THIS SERIES B COMMON STOCK PURCHASE WARRANT (the “Warrant”) certifies that, for value received, or its assigns (the “Holder”) is entitled, upon the terms and subject to the limitations on exercise and the conditions hereinafter set forth, at any time on or after [the Stockholder

Form of Placement Agent Warrant issued in this Offering.

Exhibit 4.27 PLACEMENT AGENT COMMON STOCK PURCHASE WARRANT soluna holdings, Inc. Warrant Shares: Issue Date: , 2025 THIS PLACEMENT AGENT COMMON STOCK PURCHASE WARRANT (the “Warrant”) certifies that, for value received, or its assigns (the “Holder”) is entitled, upon the terms and subject to the limitations on exercise and the conditions hereinafter set forth, at any time on or after [the Stockhold

Form of Securities Purchase Agreement (incorporated by reference to Exhibit 10.113 to the Company’s Registration Statement on Form S-1/A (File No. 333-287519) filed on June 16, 2025).

Exhibit 10.113 SECURITIES PURCHASE AGREEMENT This Securities Purchase Agreement (this “Agreement”) is dated as of , 2025, between Soluna Holdings, Inc., a Nevada corporation (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

Filing Fee Table

Exhibit 107 Calculation of Filing Fee Tables Form S-1 (Form Type) Soluna Holdings, Inc.

As filed with the Securities and Exchange Commission on June 16, 2025

As filed with the Securities and Exchange Commission on June 16, 2025 Registration No.

Form of Pre-Funded Warrant issued in this Offering.

EXHIBIT 4.24 EXHIBIT B PRE-FUNDED COMMON STOCK PURCHASE WARRANT soluna holdings, Inc. Warrant Shares: Initial Exercise Date: , 2025 THIS PRE-FUNDED COMMON STOCK PURCHASE WARRANT (the “Warrant”) certifies that, for value received, or its assigns (the “Holder”) is entitled, upon the terms and subject to the limitations on exercise and the conditions hereinafter set forth, at any time on or after the

Form of Series A Warrant issued in this Offering.

EXHIBIT 4.25 EXHIBIT C-1 SERIES A COMMON STOCK PURCHASE WARRANT soluna holdings, Inc. Warrant Shares: Issue Date: , 2025 THIS SERIES A COMMON STOCK PURCHASE WARRANT (the “Warrant”) certifies that, for value received, or its assigns (the “Holder”) is entitled, upon the terms and subject to the limitations on exercise and the conditions hereinafter set forth, at any time on or after [the Stockholder

Soluna Inks $20M from Spring Lane Capital to Launch Project Kati 1 New Construction to Begin in Q3 2025 Spring Lane to support up to $100M for pipeline

Exhibit 99.1 Soluna Inks $20M from Spring Lane Capital to Launch Project Kati 1 New Construction to Begin in Q3 2025 Spring Lane to support up to $100M for pipeline ALBANY, NY, June 11, 2025 – Soluna Holdings, Inc. (“Soluna” or the “Company”), (NASDAQ: SLNH), a developer of green data centers for intensive computing applications, including Bitcoin mining and AI, today announced financing from Spri

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): June 11, 2025 SOLUNA HOLDINGS, IN

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): June 11, 2025 SOLUNA HOLDINGS, INC. (Exact name of Registrant as Specified in Its Charter) Nevada 001-40261 14-1462255 (State or Other Jurisdiction of Incorporation) (Commission File

Regulation FD Disclosure, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): June 5, 2025 SOLUNA HOLDINGS, INC. (Exact name of Registrant as Specified in Its Charter) Nevada 001-40261 14-1462255 (State or Other Jurisdiction of Incorporation) (Commission File N

Soluna Announces Monthly Business Update Customer Deployments Begin at Project Dorothy 2: Phase 1, and Project Sophie Achieves a Record 1.0 EH/s

Exhibit 99.1 Soluna Announces Monthly Business Update Customer Deployments Begin at Project Dorothy 2: Phase 1, and Project Sophie Achieves a Record 1.0 EH/s ALBANY, NY, June 5, 2025 – Soluna Holdings, Inc. (“Soluna” or the “Company”), (NASDAQ: SLNH), a developer of green data centers for intensive computing applications, including Bitcoin mining and AI, announced its May 2025 project site-level o

Filing Fee Table.

Exhibit 107 CALCULATION OF FILING FEE TABLE Form S-8 (Form Type) Soluna Holdings, Inc.

As filed with the Securities and Exchange Commission on May 30, 2025

As filed with the Securities and Exchange Commission on May 30, 2025 Registration No.

Regulation FD Disclosure, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 29, 2025 SOLUNA HOLDINGS, INC. (Exact name of Registrant as Specified in Its Charter) Nevada 001-40261 14-1462255 (State or Other Jurisdiction of Incorporation) (Commission File N

Ask Me Anything (AMA): Answering Investors’ Recently Asked Questions

Exhibit 99.1 Ask Me Anything (AMA): Answering Investors’ Recently Asked Questions Welcome to another installment of Soluna’s AMA (Ask Me Anything) series, where you, our readers, and our followers on Twitter and LinkedIn, can get your questions answered. In this Q&A, John Tunison, CFO of Soluna, answers shareholders’ and potential investors’ most-asked questions. Learn how to submit your questions

Soluna to Launch First Solar-Powered Data Center with 75 MW Project Signs Term Sheet to Expand Pipeline with Project Annie

Exhibit 99.1 Soluna to Launch First Solar-Powered Data Center with 75 MW Project Signs Term Sheet to Expand Pipeline with Project Annie ALBANY, NY, May 22, 2025 – Soluna Holdings, Inc. (“Soluna” or the “Company”), (NASDAQ: SLNH), a developer of green data centers for intensive computing applications, including Bitcoin mining and AI, announced today that it has signed a term sheet for power for Pro

Filing Fee Table

EXHIBIT 107 Calculation of Filing Fee Tables Form S-1 (Form Type) Soluna Holdings, Inc.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 22, 2025 SOLUNA HOLDINGS, INC

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 22, 2025 SOLUNA HOLDINGS, INC. (Exact name of Registrant as Specified in Its Charter) Nevada 001-40261 14-1462255 (State or Other Jurisdiction of Incorporation) (Commission File N

As filed with the Securities and Exchange Commission on May 22, 2025

As filed with the Securities and Exchange Commission on May 22, 2025 Registration No.

Presentation, dated May 16, 2025

Exhibit 99.1

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 16, 2025 SOLUNA HOLDINGS, INC

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 16, 2025 SOLUNA HOLDINGS, INC. (Exact name of Registrant as Specified in Its Charter) Nevada 001-40261 14-1462255 (State or Other Jurisdiction of Incorporation) (Commission File N

Results of Operations and Financial Condition, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 16, 2025 SOLUNA HOLDINGS, INC. (Exact name of Registrant as Specified in Its Charter) Nevada 001-40261 14-1462255 (State or Other Jurisdiction of Incorporation) (Commission File N

Soluna Reports Q1’25 Results Q1 Revenue of $5.9 Million and 220MW of New Projects in Development

Exhibit 99.1 Soluna Reports Q1’25 Results Q1 Revenue of $5.9 Million and 220MW of New Projects in Development ALBANY, NY, May 16, 2025 - Soluna Holdings, Inc. (“Soluna” or the “Company”) (NASDAQ: SLNH), a developer of green data centers for intensive computing applications, including Bitcoin mining and AI, announced its financial results for the quarter year ended March 31, 2025. “Our outlook shin

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended March 31, 2025 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number: 001-40261 Soluna Holdings, Inc

Soluna Announces Monthly Business Update

Exhibit 99.1 Soluna Announces Monthly Business Update ALBANY, NY, May 8, 2025 – Soluna Holdings, Inc. (“Soluna” or the “Company”), (NASDAQ: SLNH), a developer of green data centers for intensive computing applications, including Bitcoin mining and AI, announced its April 2025 project site-level operations, developments, and updates. The Company has provided the following Corporate and Site Updates

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 8, 2025 SOLUNA HOLDINGS, INC.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 8, 2025 SOLUNA HOLDINGS, INC. (Exact name of Registrant as Specified in Its Charter) Nevada 001-40261 14-1462255 (State or Other Jurisdiction of Incorporation) (Commission File Nu

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 8, 2025 SOLUNA HOLDINGS, INC.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 8, 2025 SOLUNA HOLDINGS, INC. (Exact name of Registrant as Specified in Its Charter) Nevada 001-40261 14-1462255 (State or Other Jurisdiction of Incorporation) (Commission File Nu

At the Market Offering Agreement, dated April 29, 2025, by and between Soluna Holdings, Inc. and H.C. Wainwright & Co., LLC (incorporated by reference to the Company’s Current Report on Form 8-K filed with the SEC on April 29, 2025)

Exhibit 1.1 AT THE MARKET OFFERING AGREEMENT April 29, 2025 H.C. Wainwright & Co., LLC 430 Park Avenue New York, New York 10022 Ladies and Gentlemen: Soluna Holdings, Inc., a corporation organized under the laws of Nevada (the “Company”), confirms its agreement (this “Agreement”) with H.C. Wainwright & Co., LLC (the “Manager”) as follows: 1. Definitions. The terms that follow, when used in this Ag

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): April 29, 2025 SOLUNA HOLDINGS, I

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): April 29, 2025 SOLUNA HOLDINGS, INC. (Exact name of Registrant as Specified in Its Charter) Nevada 001-40261 14-1462255 (State or Other Jurisdiction of Incorporation) (Commission File

Up to $3,750,000 Common Stock

Filed Pursuant to Rule 424(b)(5) Registration No. 333-286638 PROSPECTUS SUPPLEMENT (To Prospectus dated April 29, 2025) Up to $3,750,000 Common Stock On April 29, 2025, we entered into a certain At the Market Offering Agreement, or Sales Agreement, with H.C. Wainwright & Co., LLC, or Wainwright, relating to shares of our common stock, par value $0.001 per share (“common stock”), offered by this pr

April 25, 2025

April 25, 2025 VIA EDGAR United States Securities and Exchange Commission Division of Corporation Finance 100 F Street, N.

LETTER

April 25, 2025 John Belizaire Chief Executive Officer Soluna Holdings, Inc. 325 Washington Ave Extension Albany, NY 12205 Re: Soluna Holdings, Inc. Registration Statement on Form S-3 Filed April 18, 2025 File No. 333-286638 Dear John Belizaire: This is to advise you that we have not reviewed and will not review your registration statement. Please refer to Rules 460 and 461 regarding requests for a

Up to 1,935,770 Shares of Common Stock

Filed Pursuant to Rule 424(b)(3) Registration No. 333-282559 PROSPECTUS Up to 1,935,770 Shares of Common Stock This prospectus relates to the offer and resale, from time to time, by the selling holders identified in this prospectus (the “Selling Holders”), or their permitted transferees, of up to 1,935,770 shares of common stock, par value $0.001 (“Common Stock”), of Soluna Holdings, Inc., a Nevad

Soluna Signs Deal with Blockware at Project Dorothy 2, Expanding Bitcoin Hosting Business New 5 MW Hosting Deal Highlights Growing Demand for Sustainable Bitcoin Infrastructure

Exhibit 99.1 Soluna Signs Deal with Blockware at Project Dorothy 2, Expanding Bitcoin Hosting Business New 5 MW Hosting Deal Highlights Growing Demand for Sustainable Bitcoin Infrastructure ALBANY, NY, April 22, 2025 – Soluna Holdings, Inc. (“Soluna” or the “Company”), (NASDAQ: SLNH), a developer of green data centers for intensive computing applications, including Bitcoin mining and AI, announced

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): April 22, 2025 SOLUNA HOLDINGS, I

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): April 22, 2025 SOLUNA HOLDINGS, INC. (Exact name of Registrant as Specified in Its Charter) Nevada 001-40261 14-1462255 (State or Other Jurisdiction of Incorporation) (Commission File

Form of Senior Note (included in Exhibit 4.4)

Exhibit 4.4 SOLUNA HOLDINGS, INC., as Issuer and ●, as Trustee INDENTURE Dated as of ● Senior Debt Securities CROSS REFERENCE SHEET1 Between Provisions of the Trust Indenture Act of 1939 and the Indenture to be dated as of , 20 between SOLUNA HOLDINGS, INC. and , as Trustee: Section of the Act Section of Indenture 310(a)(1) and (2) 5.08 310(a)(3) and (4) Inapplicable 310(b) 5.09(a), (b) and (d) 31

Form of Subordinated Note (included in Exhibit 4.5)

Exhibit 4.5 SOLUNA HOLDINGS, INC., as Issuer and ●, as Trustee INDENTURE Dated as of ● Subordinated Debt Securities CROSS REFERENCE SHEET1 Between Provisions of the Trust Indenture Act of 1939 and the Indenture to be dated as of , 20 between SOLUNA HOLDINGS, INC. and , as Trustee: Section of the Act Section of Indenture 310(a)(1) and (2) 5.08 310(a)(3) and (4) Inapplicable 310(b) 5.09(a), (b) and

As filed with the Securities and Exchange Commission on April 18, 2025

As filed with the Securities and Exchange Commission on April 18, 2025 Registration No.

Filing Fee Table

EXHIBIT 107 Calculation of Filing Fee Tables Form S-3 (Form Type) Soluna Holdings, Inc.

As filed with the Securities and Exchange Commission on April 18, 2025

As filed with the Securities and Exchange Commission on April 18, 2025 Registration No.

Soluna To Expand Renewable-Powered AI & Bitcoin Computing with New 100MW Site Project Ellen to Tap Texas Wind for Data Centers

Exhibit 99.1 Soluna To Expand Renewable-Powered AI & Bitcoin Computing with New 100MW Site Project Ellen to Tap Texas Wind for Data Centers Albany, NY – April 17, 2025 – Soluna Holdings, Inc. (“Soluna” or the “Company”), (NASDAQ: SLNH), a developer of green data centers for intensive computing applications, including Bitcoin mining and AI, announced today that it has signed a term sheet for power

Regulation FD Disclosure, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): April 17, 2025 SOLUNA HOLDINGS, INC. (Exact name of Registrant as Specified in Its Charter) Nevada 001-40261 14-1462255 (State or Other Jurisdiction of Incorporation) (Commission File

Soluna Signs Land Agreements for 166 MW Project Kati Targets Sustainable AI and Bitcoin Growth

Exhibit 99.1 Soluna Signs Land Agreements for 166 MW Project Kati Targets Sustainable AI and Bitcoin Growth ALBANY, NY, April 15, 2025 –Soluna Holdings, Inc. (“Soluna” or the “Company”), (NASDAQ: SLNH), a developer of green data centers for intensive computing applications including Bitcoin mining and AI, announced today that it has signed the necessary definitive agreements to secure two parcels

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): April 15, 2025 SOLUNA HOLDINGS, I

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): April 15, 2025 SOLUNA HOLDINGS, INC. (Exact name of Registrant as Specified in Its Charter) Nevada 001-40261 14-1462255 (State or Other Jurisdiction of Incorporation) (Commission File

FAQ FOR HPE TERMINATION EVENT

Exhibit 99.2 FAQ FOR HPE TERMINATION EVENT Forward Looking Statements This series of “Frequently Asked Questions” contains forward-looking statements. These statements are made under the “safe harbor” provisions of the U.S. Private Securities Litigation Reform Act of 1995. These forward-looking statements include all statements, other than statements of historical fact, regarding our current views

Regulation FD Disclosure, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): April 10, 2025 SOLUNA HOLDINGS, INC. (Exact name of Registrant as Specified in Its Charter) Nevada 001-40261 14-1462255 (State or Other Jurisdiction of Incorporation) (Commission File

Soluna Announces Monthly Business Update Company Receives Second Patent Award

Exhibit 99.1 Soluna Announces Monthly Business Update Company Receives Second Patent Award ALBANY, NY, April 10, 2025 – Soluna Holdings, Inc. (“Soluna” or the “Company”), (NASDAQ: SLNH), a developer of green data centers for intensive computing applications, including Bitcoin mining and AI, announced its March 2025 project site-level operations, developments, and updates. The Company has provided

Soluna Strengthens Texas Presence with New 120MW Wind-Powered Data Center Project Signed Term Sheet Expected to Unlock Scalable, Sustainable Computing in Cameron County with Project Hedy

Exhibit 99.1 Soluna Strengthens Texas Presence with New 120MW Wind-Powered Data Center Project Signed Term Sheet Expected to Unlock Scalable, Sustainable Computing in Cameron County with Project Hedy Albany, NY – April 8, 2025 – Soluna Holdings, Inc. (“Soluna” or the “Company”), (NASDAQ: SLNH), a developer of green data centers for intensive computing applications, including Bitcoin mining and AI,

Regulation FD Disclosure, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): April 8, 2025 SOLUNA HOLDINGS, INC. (Exact name of Registrant as Specified in Its Charter) Nevada 001-40261 14-1462255 (State or Other Jurisdiction of Incorporation) (Commission File

Results of Operations and Financial Condition, Other Events, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): April 1, 2025 SOLUNA HOLDINGS, INC. (Exact name of Registrant as Specified in Its Charter) Nevada 001-40261 14-1462255 (State or Other Jurisdiction of Incorporation) (Commission File

Soluna Reports Revenue Growth of 80.5% to $38 million for 2024 Project pipeline growth, cash growth, and capital structure simplification highlight the focus and execution in core business.

Exhibit 99.1 Soluna Reports Revenue Growth of 80.5% to $38 million for 2024 Project pipeline growth, cash growth, and capital structure simplification highlight the focus and execution in core business. ALBANY, NY, April 1, 2025 - Soluna Holdings, Inc. (“Soluna Holdings” or the “Company”), (NASDAQ: SLNH), a developer of green data centers for intensive computing applications including Bitcoin mini

Subsidiaries of Securities (incorporated by reference to the Company’s Annual Report on Form 10-K filed with the SEC on March 31, 2025)

Exhibit 21 SUBSIDIARIES OF SOLUNA HOLDINGS, INC. Subsidiary Name Jurisdiction of Incorporation or Organization Soluna Callisto Holdings, Inc. Delaware Soluna Digital, Inc. Nevada Soluna Global Services, Inc. Nevada Soluna Cloud, Inc. Nevada Soluna Energy, Inc. Nevada SUBSIDIARIES OF SOLUNA DIGITAL, INC. Subsidiary Name Jurisdiction of Incorporation or Organization Soluna MC, LLC Nevada Soluna SW H

Soluna Holdings, Inc. Insider Trading Policy

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