Soluna Holdings, Inc

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. )

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Filed by a party other than the Registranto

Check the appropriate box:

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325 WASHINGTON AVENUE EXTENSION

ALBANY, NEW YORK 12205

NOTICE OF ANNUAL MEETING OF STOCKHOLDERS

To be held on October 16, 2026

To the Stockholders of Soluna Holdings, Inc.

You are cordially invited to attend the Annual Meeting of Stockholders (the “Annual Meeting”) of Soluna Holdings, Inc. (the “Company”) to be held on October 16, 2026, at 10:00 a.m., Eastern Time. The Annual Meeting will be held virtually at the following virtual meeting link www.virtualshareholdermeeting.com/SLNH2026. You will be able to participate in the Annual Meeting as well as vote and submit your questions and examine our stockholder list during the live webcast of the Annual Meeting by visiting www.virtualshareholdermeeting.com/SLNH2026 and entering the 16-digit control number included on your proxy card (the “Proxy Card”). At the Annual Meeting, stockholders will be asked to consider and act upon the following matters:

•To elect three director nominees to serve as Class III directors of the Board of Directors for three-year terms expiring at the annual meeting of stockholders in 2029;

•To approve an amendment to the Company’s Articles of Incorporation, as amended, to increase the number of shares of common stock of the Company, par value $0.001 per share (the “common stock”), authorized for issuance thereunder from 375,000,000 shares to 1,000,000,000 shares;

•To approve, on an advisory basis, the executive compensation of the Company's named executive officers as described in the attached proxy statement;

•To ratify the appointment of KPMG LLP as our independent registered public accounting firm for the year ending December 31, 2026;

•To approve, for purposes of complying with Nasdaq Listing Rule 5635(d), the potential issuance of 20% or more of the Company’s issued and outstanding shares of common stock pursuant to the Standby Equity Purchase Agreement between the Company and YA II PN, Ltd., dated March 24, 2026;

•To approve the adjournment of the Annual Meeting in the event that the number of shares of common stock present or represented by proxy at the Annual Meeting and voting “FOR” the approval of any of the foregoing proposals are insufficient to approve such proposal; and

•To consider any other matters that may properly come before the Annual Meeting, including any adjournment or postponement thereof.

On or about August 24, 2026, we intend to begin sending to our stockholders a Notice of Annual Meeting of Stockholders (the "Notice") along with our proxy statement for the Annual Meeting, our 2025 Annual Report on Form 10-K and a proxy card. The proxy statement and accompanying materials also provide instructions on how to vote online.

Only holders of our common stock at the close of business on August 21, 2026 are entitled to receive notice of and to vote at the Annual Meeting or any postponement or adjournment thereof.

Your vote is important. Whether or not you plan to attend the Annual Meeting, please submit your proxy to vote electronically via the Internet or by telephone, or please complete, sign, date and return the accompanying proxy card or voting instruction card in the enclosed postage-paid envelope. If you attend the Annual Meeting and prefer to vote during the Annual Meeting, you may do so even if you have already submitted a proxy to vote your shares. You may revoke your proxy in the manner described in the proxy statement at any time before it has been voted at the Annual Meeting.

PROXY STATEMENT TABLE OF CONTENTS

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325 WASHINGTON AVENUE EXTENSION

ALBANY, NEW YORK 12205

PROXY STATEMENT

This proxy statement (this “Proxy Statement”) contains information related to the 2026 Annual Meeting of Stockholders (the “Annual Meeting”) of Soluna Holdings, Inc. (collectively, “we,” “us,” “our” or the “Company”) to be held on October 16, 2026 at 10:00 am Eastern Time. The Annual Meeting will be held virtually via a live webcast by visiting www.virtualshareholdermeeting.com/SLNH2026, or at such other time and place to which the Annual Meeting may be adjourned or postponed. In order to attend our Annual Meeting, you must log in to the Annual Meeting at www.virtualsharehol dermeeting.com/SLNH2026 using the 16-digit control number provided to you on the proxy card that accompanied the proxy materials. In addition, unless the context otherwise requires, references to “stockholders” of record are to the holders of our common stock, par value $0.001 per share (the “common stock”), on August 21, 2026 (the “Record Date”). Stockholders attending the virtual meeting will be afforded the same rights and opportunities to participate in the Annual Meeting as they would be afforded at an in-person meeting.

Proxies for the Annual Meeting are being solicited by the Board of Directors (the “Board”) of the Company. A Notice of Annual Meeting of Stockholders (the "Notice") and this Proxy Statement are first being made available to stockholders on orabout August 24, 2026.

Important Notice Regarding the Availability of Proxy Materials for the Stockholder Meeting To Be Held on October 16, 2026:

Our proxy materials including our Notice of Annual Meeting of Stockholders, this Proxy Statement for the Annual Meeting, our Annual Report on Form 10-K for the fiscal year ended December 31, 2025 and proxy card are available on the Internet at www.proxyvote.com. Under Securities and Exchange Commission (the “SEC”) rules, we are providing access to our proxy materials by notifying you of the availability of our proxy materials on the Internet.