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 22, 2026

SPRING VALLEY ACQUISITION CORP. III

(Exact name of registrant as specified in its charter)

Cayman Islands |  | 001-42822 |  | N/A
(State or other jurisdiction of incorporation) |  | (Commission File Number) |  | (IRS Employer Identification No.)

2100 McKinney Ave., Suite 1675 Dallas, TX |  | 75201
(Address of principal executive offices) |  | (Zip Code)

Registrant’s telephone number, including area code: (214) 308-5230

Not Applicable

(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:

x | 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
Units, each consisting of one Class A ordinary share and one-third of one redeemable public warrant |  | SVIIIU |  | The Nasdaq Stock Market LLC
Class A ordinary shares, par value $0.0001 per share |  | SVIII |  | The Nasdaq Stock Market LLC
Warrants, each whole warrant exercisable for one Class A ordinary share at an exercise price of $11.50 |  | SVIIIW |  | 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 x

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 January 22, 2026, Spring Valley Acquisition Corp. III (“SVIII”) and General Fusion Inc. (the “Company” or “General Fusion”) issued a press release announcing their execution of (i) a definitive Business Combination Agreement, dated January 21, 2026 (the “Business Combination Agreement”) pursuant to which, among other things, SVIII and General Fusion would combine and General Fusion would become a public company and (ii) securities purchase agreements, dated January 21, 2026, pursuant to which the Company would consummate a private placement of approximately US$105 million of convertible preferred shares and warrants with certain institutional investors. A copy of the press release is furnished herewith as Exhibit 99.1 and incorporated into this Item 7.01 by reference.

Attached hereto as Exhibit 99.2 and incorporated into this Item 7.01 by reference is a form of presentation to be used by the Company and SVIII in presentations for certain of the Company’s and SVIII’s shareholders and other persons.

The information in this Item 7.01, including Exhibits 99.1 and 99.2, is furnished and shall not be deemed to be “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or otherwise be subject to the liabilities of that section, nor shall it be deemed to be incorporated by reference in any filing under the Securities Act of 1933, as amended (the “Securities Act”), or the Exchange Act, except as expressly set forth by specific reference in such filing.

Additional Information and Where to Find It

In connection with the transactions contemplated by the Business Combination Agreement (the “Business Combination”), SVIII intends to file with the Securities and Exchange Commission (the “SEC”) a registration statement on Form F-4 (the “Registration Statement”), which will include a prospectus with respect to SVIII’s securities to be issued in connection with the proposed Business Combination and a proxy statement to be distributed to holders of SVIII’s Class A ordinary shares in connection with SVIII’s solicitation of proxies for the vote by SVIII’s shareholders with respect to the proposed Business Combination and other matters to be described in the Registration Statement (the “Proxy Statement”). After the SEC declares the Registration Statement effective, SVIII plans to file the definitive Proxy Statement with the SEC and to mail copies to SVII’s shareholders as of a record date to be established for voting on the proposed Business Combination and other matters to be described in the Registration Statement. This document does not contain all the information that should be considered concerning the proposed Business Combination and is not a substitute for the Registration Statement, Proxy Statement or for any other document that SVIII may file with the SEC. Before making any investment or voting decision, investors and security holders of SVIII and the Company are urged to read the Registration Statement and the Proxy Statement, and any amendments or supplements thereto, as well as all other relevant materials filed or that will be filed with the SEC in connection with the proposed Business Combination as they become available because they will contain important information about the Company, SVIII and the proposed Business Combination. Investors and security holders will be able to obtain free copies of the Registration Statement, the Proxy Statement and all other relevant documents filed or that will be filed with the SEC by SVIII through the website maintained by the SEC at www.sec.gov. In addition, the documents filed by SVIII may be obtained free of charge from SVIII’s website at www.sv-ac.com or by directing a request to Spring Valley Acquisition Corp. III, Attn: Corporate Secretary, 2100 McKinney Avenue, Suite 1675, Dallas, Texas 75201. The information contained on, or that may be accessed through, the websites referenced in this document is not incorporated by reference into, and is not a part of, this document.

Participants in the Solicitation

The Company, SVIII and their respective directors, executive officers and other members of management and employees may, under the rules of the SEC, be deemed to be participants in the solicitations of proxies from SVIII’s shareholders in connection with the proposed Business Combination. For more information about the names, affiliations and interests of SVIII’s directors and executive officers, please refer to the final prospectus from SVIII’s initial public offering, which was dated September 3, 2025 and filed with the SEC on September 4, 2025 (the “IPO Prospectus”) and the Registration Statement, Proxy Statement and other relevant materials filed or to be filed with the SEC in connection with the proposed Business Combination when they become available. Additional information regarding the participants in the proxy solicitation and a description of their direct and indirect interests, which may, in some cases, be different than those of SVIII’s shareholders generally, will be included in the Registration Statement and the Proxy Statement, when they become available. Shareholders, potential investors and other interested persons should read the Registration Statement and the Proxy Statement carefully, when they become available, before making any voting or investment decisions. You may obtain free copies of these documents from the sources indicated above.

No Offer or Solicitation

This document shall not constitute a “solicitation” as defined in Section 14 of the Exchange Act. This document shall not constitute an offer to sell or exchange, the solicitation of an offer to buy or a recommendation to purchase, any securities, or a solicitation of any vote, consent or approval, nor shall there be any sale, issuance or transfer of securities in any jurisdiction in which such offer, solicitation or sale may be unlawful under the laws of such jurisdiction. No offering of securities in the proposed Business Combination shall be made except by means of a prospectus meeting the requirements of the Securities Act or an exemption therefrom.

Cautionary Note Regarding Forward-Looking Statements

Certain statements included in this document are not historical facts but are forward-looking statements for purposes of the safe harbor provisions under the United States Private Securities Litigation Reform Act of 1995. All statements other than statements of historical facts contained in this document are forward-looking statements. Any statements that refer to projections, forecasts or other characterizations of future events or circumstances, including any underlying assumptions, are also forward-looking statements. In some cases, you can identify forward-looking statements by words such as “estimate,” “plan,” “project,” “forecast,” “intend,” “expect,” “anticipate,” “believe,” “seek,” “strategy,” “future,” “opportunity,” “may,” “target,” “should,” “will,” “would,” “will be,” “will continue,” “will likely result,” “preliminary,” or similar expressions that predict or indicate future events or trends or that are not statements of historical matters, but the absence of these words does not mean that a statement is not forward-looking. Forward-looking statements include, without limitation, SVIII’s, General Fusion’s, or their respective management teams’ expectations concerning the proposed Business Combination and expected benefits or timing thereof; the outlook for General Fusion’s business, including its ability to commercialize magnetized target fusion (“MTF”) or any other fusion technology on its expected timeline or at all; statements regarding the current and expected results of General Fusion’s Lawson Machine 26 (“LM26”) program; the ability to execute General Fusion’s strategies, including on any expected timeline or anticipated cost basis; projected and estimated financial performance; anticipated industry trends; future capital expenditures; government regulation of fusion energy; and environmental risks; as well as any information concerning possible or assumed future results of operations of General Fusion. The forward-looking statements are based on the current expectations of the respective management teams of SVIII and General Fusion, as applicable, and are inherently subject to uncertainties and changes in circumstance and their potential effects. There can be no assurance that future developments will be those that have been anticipated. These forward-looking statements involve a number of risks, uncertainties or other assumptions that may cause actual results or performance to be materially different from those expressed or implied by these forward-looking statements. These risks and uncertainties include, but are not limited to, (i) the risk that the proposed Business Combination may not be completed in a timely manner or at all, which may adversely affect the price of SVIII’s securities; (ii) the failure to satisfy the conditions to the consummation of the proposed Business Combination, including the adoption of the Business Combination Agreement by the shareholders of SVIII and the receipt of regulatory approvals; (iii) market risks; (iv) the occurrence of any event, change or other circumstance that could give rise to the termination of the Business Combination Agreement; (v) the effect of the announcement or pendency of the proposed Business Combination on General Fusion’s business relationships, performance, and business generally; (vi) risks that the proposed Business Combination disrupts current plans of General Fusion and potential difficulties in its employee retention as a result of the proposed Business Combination; (vii) the outcome of any legal proceedings that may be instituted against General Fusion or SVIII related to the Business Combination Agreement or the proposed Business Combination; (viii) failure to realize the anticipated benefits of the proposed Business Combination; (ix) the inability to maintain the listing of SVIII’s securities or to meet listing requirements and maintain the listing of the combined company’s securities on Nasdaq; (x) the risk that the proposed Business Combination may not be completed by SVIII’s business combination deadline and the potential failure to obtain an extension of the business combination deadline if sought by SVIII; (xi) the risk that the price of the combined company’s securities may be volatile due to a variety of factors, including changes in laws, regulations, technologies, natural disasters, national security tensions, and macro-economic and social environments affecting its business; (xii) laws and regulations governing General Fusion’s research and development activities, and changes in such laws and regulations; (xiii) any failure to commercialize MTF on the expected timeline or at all, including any failure to achieve the objectives of the LM26 program; (xiv) environmental regulations and legislation; (xv) the effects of climate change, extreme weather events, water scarcity, and seismic events, and the effectiveness of strategies to deal with these issues; (xvi) fluctuations in currency markets; (xvii) General Fusion’s ability to complete and successfully integrate any future acquisitions; (xviii) increased competition in the fusion industry; (xix) limited supply of materials and supply chain disruptions; and (xx) the risk that the private placement may not be completed, or that other capital needed by the combined company may not be raised on favorable terms, or at all, including as a result of the restrictions agreed to in connection with the private placement. The foregoing list is not exhaustive, and there may be additional risks that neither SVIII nor General Fusion presently know or that SVIII and General Fusion currently believe are immaterial. You should carefully consider the foregoing factors, any other factors discussed in this document and the other risks and uncertainties described in the “Risk Factors” section of the IPO Prospectus and the risks to be described in the Registration Statement; and those discussed and identified in filings made with the SEC by SVIII from time to time. General Fusion and SVIII caution you against placing undue reliance on forward-looking statements, which reflect current beliefs and are based on information currently available as of the date a forward-looking statement is made. Forward-looking statements set forth in this document speak only as of the date of this document. Neither General Fusion nor SVIII undertakes any obligation to revise forward-looking statements to reflect future events, changes in circumstances, or changes in beliefs. In the event that any forward-looking statement is updated, no inference should be made that General Fusion or SVIII will make additional updates with respect to that statement, related matters, or any other forward-looking statements. Any corrections or revisions and other important assumptions and factors that could cause actual results to differ materially from forward-looking statements, including discussions of significant risk factors, may appear, up to the consummation of the proposed Business Combination, in SVIII’s public filings with the SEC, which are or will be (as applicable) accessible at www.sec.gov, and which you are advised to review carefully.

Item 9.01 Financial Statements and Exhibits.

(d) Exhibits

Exhibit No. |  | Description
99.1 |  | Joint Press Release, dated January 22, 2026.
99.2 |  | Investor Presentation, dated January 2026.
104 |  | Cover Page Interactive Data File (embedded with the Inline XRBL document).

SIGNATURE

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

| SPRING VALLEY ACQUISITION CORP. III
| By: | /s/ Christopher Sorrels
| Name: | Christopher Sorrels
| Title: | Chief Executive Officer and Chairman
Dated: January 22, 2026 |  |