Amendment: SEC Form S-3/A filed by Soluna Holdings Inc.

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)

325 Washington Avenue Extension

Albany, New York 12205

(516) 216-9257

(Address, including zip code, and telephone number,

including area code, of registrant’s principal executive offices)

John Belizaire

Chief Executive Officer

Soluna Holdings, Inc.

325 Washington Ave Extension

Albany, New York 12205

(516) 216-9257

(Name, address, including zip code, and telephone number,

including area code, of agent for service)

Copies of all communications, including communications sent to the agent for service, to:

Steven E. Siesser, Esq.

Daniel L. Forman, Esq.

Lowenstein Sandler LLP

1251 Avenue of the Americas

New York, New York 10020

(212) 204-8688

Approximate date of commencement of proposed sale to the public: From time to time after this Registration Statement becomes effective.

If the only securities being registered on this Form are being offered pursuant to dividend or interest reinvestment plans, please check the following box: ☐

If any of the securities being registered on this Form are to be offered on a delayed or continuous basis pursuant to Rule 415 under the Securities Act of 1933, other than securities offered only in connection with dividend or interest reinvestment plans, check the following box: ☒

If this Form is filed to register additional securities for an offering pursuant to Rule 462(b) under the Securities Act, please check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering. ☐

If this Form is a post-effective amendment filed pursuant to Rule 462(c) under the Securities Act, check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering. ☐

If this Form is a registration statement pursuant to General Instruction I.D. or a post-effective amendment thereto that shall become effective upon filing with the Commission pursuant to Rule 462(e) under the Securities Act, check the following box. ☐

If this Form is a post-effective amendment to a registration statement filed pursuant to General Instruction I.D. filed to register additional securities or additional classes of securities pursuant to Rule 413(b) under the Securities Act, check the following box. ☐

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smaller reporting company, or an emerging growth company. See the definitions of “large accelerated filer,” “accelerated filer,” “smaller reporting company” and “emerging growth company” in Rule 12b-2 of the Exchange Act.

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 7(a)(2)(B) of Securities Act. ☐

The Registrant hereby amends this Registration Statement on such date or dates as may be necessary to delay its effective date until the Registrant shall file a further amendment which specifically states that this Registration Statement shall thereafter become effective in accordance with Section 8(a) of the Securities Act of 1933 or until the Registration Statement shall become effective on such date as the Commission acting pursuant to said Section 8(a), may determine.

EXPLANATORY NOTE

We are filing this pre-effective amendment (this “Amendment”) to our Registration Statement on Form S-3 (File No. 333-294152), initially filed with the U.S. Securities and Exchange Commission (the “SEC”) on March 9, 2026 (the “Registration Statement”), as an exhibits-only filing to file an updated auditor consent in Exhibit 23.1. Accordingly, this Amendment consists only of the facing page, this explanatory note, Item 16 of Part II of the Registration Statement, including the signature page and the exhibit index, and the filed exhibits. The prospectuses are unchanged and have been omitted.

Item 16. Exhibits and Financial Statement Schedules.

SIGNATURES

Pursuant to the requirements of the Securities Act of 1933, the Registrant certifies that it has reasonable grounds to believe that it meets all of the requirements for filing on Form S-3 and has duly caused this Registration Statement to be signed on its behalf by the undersigned, thereunto duly authorized, in the City of Albany, New York, on March 30, 2026.

Pursuant to the requirements of the Securities Act of 1933, this Registration Statement has been signed by the following persons in the capacities held on the dates indicated: