Forum Markets Inc. 美国存托凭证招股说明书（2026年4月8日版）

FORUM MARKETS, INCORPORATED(f/k/a ETHZILLA CORPORATION) Up to $500,000,000 Common Stock This prospectus supplement supplements and amends the prospectus supplement dated August 13, 2025 (as amended andsupplemented, the “prospectus supplement”) relating to the offer and sale of our shares of common stock having an aggregate offeringprice of up to $500,000,000, from time to time through or to Clear Street LLC (“Clear Street”) as sales agent or principal pursuant to On August 22, 2025 and November 14, 2025, we amended and restated the Sales Agreement (as amended, the “Existing SalesAgreement”) to, among other things, change the registration statement and prospectus supplement pursuant to which sales of ourcommon stock were to be made to an “automatic shelf registration statement,” and to include TCBI Securities, Inc., doing business as On April 8, 2026, we amended and restated the Existing Sales Agreement to, among other things, change the registration statement andprospectus supplement pursuant to which sales of our common stock were to be made to our registration statement on Form S-3 (FileNo. 333-288194). This prospectus supplement is being filed to include Texas Capital Securities as a sales agent, in addition to ClearStreet, in connection with the offer and sale of up to $500,000,000 of our shares of common stock from time to time in negotiated THIS IS NOT A NEW REGISTRATION OF SECURITIES. This prospectus supplement should be read in conjunction with the prospectuses, which are to be delivered with this prospectussupplement. This prospectus supplement is qualified by reference to the prospectuses, except to the extent that the information in this This prospectus supplement is not complete without, and may not be delivered or utilized except in connection with, the prospectuses. Investing in our common stock involves a high degree of risk. You should read this prospectus supplement, the accompanyingprospectus and the documents incorporated by reference into the prospectus supplement and therein before you make yourinvestment decision. See “Risk Factors” beginning on page S-3 of this prospectus supplement and page 5 of the accompanying NEITHER THE SECURITIES AND EXCHANGE COMMISSION NOR ANY STATE SECURITIES COMMISSION HASAPPROVED OR DISAPPROVED OF THESE SECURITIES OR DETERMINED IF THIS PROSPECTUS SUPPLEMENTIS TRUTHFUL OR COMPLETE. ANY REPRESENTATION TO THE CONTRARY IS A CRIMINAL OFFENSE. Texas Capital Securities Clear Street The date of this prospectus supplement is April 8, 2026. Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrantunder any of the following provisions (seeGeneral Instruction A.2. below): ☐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: Item 1.01 Entry into a Material Definitive Agreement. Second Amended and Restated Sales Agreement As previously reported, on August 13, 2025, Forum Markets, Incorporated (formerly ETHZilla Corporation, which was formerly 180Life Sciences Corp.) (the “Company”) entered into a Sales Agreement (the “Initial Sales Agreement”) with Clear Street LLC (“ClearStreet”) to sell from time to time through Clear Street, acting as sales agent for the Company’s “at the market offering” program,shares of the Company’s common stock, par value $0.0001 per share (the “Common Stock”) pursuant to the Company’s registrationstatement on Form S-3 (File No. 333-288194) (the “June Registration Statement”) and the prospectus supplement initially filed onAugust 13, 2025 (the “Initial Prospectus Supplement”). On August 22, 2025, the Company entered into an Amended and RestatedSales Agreement (the “Amended Sales Agreement”) with Clear Street to, among other things, change the registration statement andprospectus supplement pursuant to which sales of the Common Stock were to be made to the registration statement on Form S-3ASR(File No. 333-289811) (the “WKSI Registration Statement”) and the prospectus supplement initially filed on August 22, 2025 (the On April 8, 2026, the Company entered into a Second Amended and Restated Sales Agreement (the “Second Amended and RestatedSales Agreement”) with the Agents to cease all sales of Common Stock pursuant to the WKSI Registration Statement and WKSIProspectus Supplement and to transition the program back to the June Registration Statement and Initial Prospectus Supplement. Fromand after the date of the Second Amended and Restated Sales Agreement, the Company will not sell any Common Stock pursuant to The foregoing description of the Second Amended and Restated Sales A