降雨增强技术控股有限公司-A股招股说明书(2025-12-17版)

5,000,000 Shares of Class A Common Stock Underlying Warrants(For Issuance) 5,914,057 Shares of Class A Common Stock(For Resale) This prospectus supplement No. 6 (this “Supplement”) supplements, updates and amends the information contained in the prospectus dated April 25,2025 (the “Prospectus”) relating to the issuance of shares of Class A common stock, par value $0.0001 per share (the “Class A Common Stock”), ofRain Enhancement Technologies Holdco, Inc. (the “Company”) upon the exercise of warrants of the Company (“Warrants”) and the resale from time to This Supplement is being filed to update and supplement the information previously included in the Prospectus with the information contained in theCompany’s Current Report on Form 8-K filed with the SEC on December 17, 2025 (the “Form 8-K”). Accordingly, we have attached the Form 8-K tothis Supplement. You should read this Supplement in conjunction with the Prospectus. This Supplement is not complete without, and may not bedelivered or used except in conjunction with, the Prospectus, including any amendments or supplements thereto. This Supplement is qualified by Our shares of Class A Common Stock and Warrants are listed on the Nasdaq Stock Market LLC (“Nasdaq”) under the symbols “RAIN” and “RAINW,”respectively. On December 16, 2025, the closing price of our Class A Common Stock was $5.92 per share and the closing price for our Warrants was We are an “emerging growth company” as defined under the federal securities laws, and, as such, may elect to comply with certain reduced publiccompany reporting requirements for this and future filings. INVESTING IN OUR SECURITIES INVOLVES RISKS. YOU SHOULD CAREFULLY CONSIDER THE RISK FACTORS SET FORTHUNDER THE SECTION ENTITLED “RISK FACTORS” ON PAGE 12 OF THE PROSPECTUS, BEFORE MAKING ANY DECISION Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of these securities orpassed upon the adequacy or accuracy of this Supplement or the accompanying Prospectus. Any representation to the contrary is a criminaloffense. The date of this prospectus supplement is December 17, 2025. Item 5.03. Amendments to Articles of Incorporation or Bylaws; Change in Fiscal Year. On December 15, 2025, Rain Enhancement Technologies Holdco, Inc. (the “Company”), filed Articles of Correction (the “Articles of Correction”) withthe Secretary of the Commonwealth of Massachusetts to correct a clerical error in the definition of Voting Threshold Date in the Company’s Amendedand Restated Articles of Organization dated December 19, 2024 (the “Articles”). The Articles of Correction is effective as of December 19, 2024, the The foregoing description of the Articles of Correction is qualified in its entirety by references to the full text of the Articles of Correction andcorrected Articles attached as Exhibit 3.1 hereto and incorporated herein by reference. Item 9.01. Financial Statements and Exhibits. (d) Exhibits. 3.1Articles of Correction to the Amended and Restated Articles of Organization of Rain Enhancement Technologies Holdco, Inc.104Cover Page Interactive Data File (embedded within the Inline XBRL document) SIGNATURES 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 theundersigned hereunto duly authorized. Date: December 17, 2025 RAIN ENHANCEMENT TECHNOLOGIES HOLDCO,INC. By:/s/ Oanh TruongName: Oanh TruongTitle:Interim Chief Financial Officer Restated Articles of Organization(General Laws Chapter 156D, Section 10.07; 950 CMR 113.35) Article I - Corporate Name The exact name of the Corporation is Rain Enhancement Technologies Holdco, Inc. (the “Corporation”). Article II - Purpose The purpose for which the Corporation is formed is for the transaction of any and all lawful business for which a business Corporation mayengage in under the Massachusetts Business Corporation Act (M.G.L. Ch. 156D, Sec. 101 et seq., as amended and in effect from time to time, the Article III - Authorized Shares The following is the total number of shares and par value of each class of stock that the Corporation is authorized to issue. The number ofauthorized shares of any class or classes of stock may be increased or decreased (but not below the number of shares thereof then outstanding or A.Common Stock 1.Voting in General. Unless and until the Corporation has issued shares of Preferred Stock having the right to vote in the election of Directors ofthe Corporation and other matters requiring action by the Corporation’s shareholders, or as otherwise provided in these Amended and Restated Articlesof Organization (as amended and/or restated from time to time, these “Articles”) or required by applicable law, the holders of shares of Class A 2.Class A Common Stock Voting. Except as otherwise provided in these Articles or required by applicable law, each holder of shares of Class ACommon Stock shall be