Plum Acquisition Corp. IV

Item 7.01. Regulation FD Disclosure. As previously disclosed on a Current Report on Form 8-K filed by Plum Acquisition Corp. IV, a publicly traded special purpose acquisition company (“Plum IV”) with the U.S. Securities and Exchange Commission (the “SEC”) on March 12, 2026, Plum IV entered into a Business Combination Agreement (as amended, the “Business Combination Agreement”) with Plum IV Merger Sub, Inc., a Delaware corporation and a direct wholly owned subsidiary of Plum IV, and Controlled Thermal Resources Holdings Inc., a Delaware corporation (the “Company”). Attached hereto as Exhibit 99.1 and incorporated into this Item 7.01 by reference is an updated form of presentation (the “Updated Investor Presentation”) to be used by the Company and Plum IV in presentations for certain of the Company’s and Plum IV’s shareholders and other persons. The Updated Investor Presentation supersedes in all respects the earlier version of an investor presentation previously furnished as Exhibit 99.1 of the Current Report on Form 8-K filed with the SEC on March 9, 2026. The information in this Item 7.01, including Exhibit 99.1, 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 “Transactions”), Plum IV and the Company intend to file with the SEC a registration statement on Form S-4 (the “Registration Statement”), which will include a preliminary proxy statement of Plum IV as well as a preliminary prospectus relating to the offer of securities to be issued to the stockholders of the Company (the “Proxy Statement/Prospectus”). After the Registration Statement is declared effective, a definitive proxy statement and other relevant documents will be mailed to shareholders of Plum IV as of the record date to be established for voting on the Transactions and other matters as described in the Proxy Statement/Prospectus. Plum IV will also file other documents regarding the Transactions with the SEC. This Current Report on Form 8-K (the “Current Report”) does not contain all of the information that should be considered concerning the Transactions and is not intended to form the basis of any investment decision or any other decision in respect of the Transactions. BEFORE MAKING ANY VOTING OR INVESTMENT DECISION, SHAREHOLDERS OF PLUM IV AND OTHER INTERESTED PARTIES ARE URGED TO READ, WHEN AVAILABLE, THE PRELIMINARY PROXY STATEMENT/PROSPECTUS, AND AMENDMENTS THERETO, AND THE DEFINITIVE PROXY STATEMENT/PROSPECTUS AND ALL OTHER RELEVANT DOCUMENTS FILED OR THAT WILL BE FILED WITH THE SEC IN CONNECTION WITH PLUM IV’S SOLICITATION OF PROXIES FOR THE EXTRAORDINARY GENERAL MEETING OF ITS SHAREHOLDERS TO BE HELD TO APPROVE THE TRANSACTIONS AND OTHER MATTERS AS DESCRIBED IN THE PROXY STATEMENT/PROSPECTUS BECAUSE THESE DOCUMENTS WILL CONTAIN IMPORTANT INFORMATION ABOUT PLUM IV, the Company AND THE TRANSACTIONS. Investors and security holders will also be able to obtain copies of the Registration Statement and the Proxy Statement/Prospectus and all other documents filed or to be filed with the SEC by Plum IV, without charge, once available, on the SEC’s website at www.sec.gov or by directing a request to: Plum Acquisition Corp. IV, 2021 Fillmore St., #2089, San Francisco, California 94115, Attention: Kanishka Roy, or by email at plumir@icrinc.com. Participants in the Solicitation Plum IV, the Company and their respective directors and executive officers may be deemed participants under SEC rules in the solicitation of proxies from Plum IV’s shareholders in connection with the Transactions. A list of the names of such directors and executive officers and information regarding their interests in the Transactions and their ownership of Plum IV’s securities is, or will be, contained in Plum IV’s filings with the SEC. Additional information regarding the interests of the persons who may, under SEC rules, be deemed participants in the solicitation of proxies from Plum IV’s shareholders in connection with the Transactions, including the names and interests of the Company’s directors and executive officers, will be set forth in the Proxy Statement/Prospectus, which is expected to be filed by Plum IV and the Company with the SEC. Investors and security holders may obtain free copies of these documents as described above. No Offer or Solicitation This Current Report is for informational purposes only and is not a proxy statement or solicitation of a proxy, consent or authorization with respect to any securities or in respect of the Transactions and shall not constitute an offer to sell or exchange, or a solicitation of an offer to buy or exchange the securities of Plum IV or the Company, or any commodity or instrument or related derivative, nor shall there be any sale of any such securities in any state or jurisdiction in which such offer, solicitation, sale or exchange would be unlawful prior to registration or qualification under the securities laws of any such state or jurisdiction. This Current Report is not, and under no circumstances is to be construed as, a prospectus, an advertisement or a public offering of the securities described herein in the United States or any other jurisdiction. No offer of securities shall be made except by means of a prospectus meeting the requirements of the Securities Act or an exemption therefrom. Investors should consult with their counsel as to the applicable requirements for a purchaser to avail itself of any exemption under the Securities Act.