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

File Number)

(IRS Employer

Identification No.)

325 Washington Avenue Extension
Albany, New York		12205
(Address of Principal Executive Offices)		(Zip Code)

Registrant’s Telephone Number, Including Area Code: (516) 216-9257

N/A

(Former Name or Former Address, if Changed Since Last Report)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

☐	Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

☐	Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

☐	Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

☐	Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Securities registered pursuant to Section 12(b) of the Act:

Title of each class	Trading Symbol(s)	Name of each exchange on which registered
Common stock, par value $0.001 per share	SLNH	The Nasdaq Stock Market LLC
9.0% Series A Cumulative Perpetual Preferred Stock, par value $0.001 per share	SLNHP	The Nasdaq Stock Market LLC

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§ 230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§ 240.12b-2 of this chapter).

Emerging growth company ☐

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 13(a) of the Exchange Act. ☐

Item 7.01 Regulation FD Disclosure.

On November 13, 2025, Soluna Holdings, Inc. (the “Company”) issued a press release announcing the completion and full energization of Project Dorothy 2, the 48 MW second phase of the Company’s flagship Project Dorothy in West Texas. A copy of the press release is attached hereto as Exhibit 99.1 and is incorporated by reference herein.

The information in Item 7.01 and in Exhibit 99.1 will not be treated as “filed” for the purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or otherwise subject to the liabilities of that section. This information will not be incorporated by reference into any filing under the Securities Act of 1933 or into another filing under the Exchange Act, unless that filing expressly incorporates this information by reference.

Item 9.01 Financial Statements and Exhibits.

(d) Exhibits.

99.1		Press Release, dated November 13, 2025

104		Cover Page Interactive Date File (embedded with the Inline XBRL document)

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, as amended, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

	SOLUNA HOLDINGS, INC.

Date: November 13, 2025	By:	/s/ David C. Michaels
		David C. Michaels
		Chief Financial Officer
		(principal financial officer)

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 completion and full energization of Project Dorothy 2, the 48 MW second phase of its flagship Project Dorothy in West Texas.

With this milestone, the 100 MW Project Dorothy campus is now fully operational — delivered on time and on budget — bringing Soluna’s total energized data center capacity to 123 MW and over 5 EH/s, a 73.3% increase since April 2025.

“Dorothy 2 represents disciplined execution and a major step forward for Soluna,” said John Belizaire, CEO of Soluna. “Our team delivered a complex, large-scale project on schedule, proving that Renewable Computing can be deployed quickly, reliably, and sustainably. It’s exciting to be growing again.”

Built behind the meter at a 150 MW wind farm, Project Dorothy converts curtailed renewable energy into productive computing power for Bitcoin mining and AI. The site’s modular design enables rapid scaling while maintaining operational efficiency and flexibility.

Powered by Soluna’s proprietary MaestroOS™ platform, the site leverages intelligent monitoring, precise data, and full-stack automation to enable faster decisions, higher uptime, and seamless grid integration.

Project Dorothy 2 Highlights:

	●	Energized in three construction phases, each delivered on time and on budget
	●	Early revenue generation began within six months of groundbreaking
	●	Now Soluna’s highest-performing site, managing over 2 EH/s independently

Key Site Milestones for Project Dorothy 1 & 2

As of November 10, 2025

	●	Total Capacity: 98 MW (Bitcoin Mining)
	●	BTC Allocation: 25 MW proprietary mining, 73 MW hosting
	●	Hosting Customers: 5 industry-leading partners
	●	Deployed Mining Rigs: >30,000
	●	Operating Hashrate: >3.9 EH/s
	●	Fleet Efficiency: 24 J/TH
	●	Uptime: >94% during operational hours
	●	Energy Consumption: ~80,000 MWh of otherwise wasted energy is used annually
	●	Power Price: $32.5/MWh

The transition to full operations for Projects Dorothy 1 and 2 has created 18 full-time local jobs, as well as additional indirect roles supporting maintenance, logistics, and services across the region.

With Project Dorothy 2 fully online, Soluna continues to advance its 1 GW+ of Renewable Computing projects, including 166 MW Project Kati, currently under construction. Each site is designed to transform underutilized renewable energy into scalable, sustainable computing infrastructure for the world’s fastest-growing digital workloads, including Bitcoin mining and AI.

Soluna continues its tradition of naming its data centers after women scientists who help catalyze major innovation. Project Dorothy is named after Dorothy Vaughan, an African American mathematician and “human computer” who worked for the National Advisory Committee for Aeronautics and NASA in 1939, exemplifying innovation and excellence in computing.

More information on Project Dorothy and Soluna’s data center projects can be found at www.solunacomputing.com.

Soluna’s glossary of terms can be found here.

Safe Harbor Statement by Soluna

This announcement 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 and assumptions with respect to future events regarding our business, our expectations with respect to the completion of Project Kati, and other statements that are predictive in nature. These forward-looking statements can be identified by terminology such as “will,” “expects,” “anticipates,” “future,” “intends,” “plans,” “believes,” “estimates,” “confident,” and similar statements. Soluna may also make written or oral forward-looking statements in its periodic reports to the U.S. Securities and Exchange Commission (“SEC”), in its annual report to shareholders, in press releases and other written materials, and in oral statements made by its officers, directors or employees to third parties. Statements that are not historical facts, including but not limited to statements about Soluna’s beliefs and expectations, are forward-looking statements. Forward-looking statements involve inherent risks and uncertainties, further information regarding which is included in the Company’s filings with the SEC. All information provided in this press release is as of the date of the press release, and Soluna undertakes no duty to update such information, except as required under applicable law.

About Soluna Holdings, Inc. (Nasdaq: SLNH)

Soluna is on a mission to make renewable energy a global superpower, using computing as a catalyst. The Company designs, develops, and operates digital infrastructure that transforms surplus renewable energy into global computing resources. Soluna’s pioneering data centers are strategically co-located with wind, solar, or hydroelectric power plants to support high-performance computing applications, including Bitcoin Mining, Generative AI, and other compute-intensive applications. Soluna’s proprietary software MaestroOS(™) helps energize a greener grid while delivering cost-effective and sustainable computing solutions and superior returns. To learn more, visit solunacomputing.com and follow us on:

LinkedIn: https://www.linkedin.com/company/solunaholdings/

X (formerly Twitter): x.com/solunaholdings

YouTube: youtube.com/c/solunacomputing

Newsletter: bit.ly/solunasubscribe

Resource Center: solunacomputing.com/resources

Soluna regularly posts important information on its website and encourages investors and potential investors to consult the Soluna investor relations and investor resources sections of its website regularly.

Contact

Public Relations

West of Fairfax for Soluna

[email protected]