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): September 15, 2026

CATALYST ACQUISITION CORP.

(Exact name of registrant as specified in its charter)

1007 Ocean Avenue, Suite 501

Santa Monica, CA 90403

(Address of principal executive offices, including zip code)

Registrant’s telephone number, including area code: (310) 404-1687

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:

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

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 8.01. Other Events.

Separate Trading of Class A Ordinary Shares and Rights

On September 15, 2026, Catalyst Acquisition Corp. (the “Company”) announced that, commencing on September 17, 2026, the holders of the units issued in its initial public offering (the “Units”), each Unit consisting of one Class A ordinary share of the Company, par value $0.0001 per share (the “Class A Ordinary Share”), and one right to receive one-seventh (1/7) of one Class A Ordinary Share upon the consummation of the Company’s initial business combination (the “Right”), may elect to separately trade the Class A Ordinary Shares and the Rights included in the Units. No fractional Rights will be issued upon separation of the Units and only whole Rights will trade. Any Units not separated will continue to trade on the Nasdaq Stock Market under the symbol “CATLU.” The Class A Ordinary Shares and the Rights are expected to trade on the Nasdaq Stock Market under the symbols “CATL” and “CATLR,” respectively. Holders of Units will need to have their brokers contact Continental Stock Transfer & Trust Company, the Company’s transfer agent, in order to separate the Units into Class A Ordinary Shares and Rights.

Item 9.01. Financial Statements and Exhibits.

(d) Exhibits

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.