Avalanche Treasury Corp-A美股招股说明书(2026-08-19版)

Up to 15,690,755 Shares of Class A Common Stock This prospectus supplement is being filed to update and supplement the information contained in the prospectus dated July 27, 2026(the “Prospectus”), related tothe resale by certain selling holders (the “Selling Holders”) of up to 15,690,755 shares of our ClassAcommon stock, par value $0.01 (“ClassA Common Stock”) with the information contained in our Quarterly Report on Form 10-Q,filed with the Securities and Exchange Commission (“SEC”) on August 19, 2026 (the “Quarterly Report”). Accordingly, we haveattached the Quarterly Report to this prospectus supplement. This prospectus supplement updates and supplements the information in the Prospectus and is not complete without, and may not bedelivered or utilized except in combination with, the Prospectus, including any amendments or supplements thereto. This prospectussupplement should be read in conjunction with the Prospectus and if there is any inconsistency between the information in theProspectus and this prospectus supplement, you should rely on the information in this prospectus supplement. Our Class A Common Stock is listed on the Nasdaq Capital Market under the symbol “AVAT”. On August 18, 2026, the closing priceof our Class A Common Stock was $0.386 per share. We are an “emerging growth company” and a “smaller reporting company” under applicable federal securities laws and aresubject to reduced public company reporting requirements. Investing in our securities involves risks. See“RISK FACTORS”beginning on page 24 of the Prospectus and in any applicableprospectus supplement. Neither the SEC nor any state securities commission has approved or disapproved of these securities or passed upon theadequacy or accuracy of the Prospectus or this prospectus supplement. Any representation to the contrary is a criminaloffense. The date of this prospectus supplement is August 19, 2026. UNITED STATESSECURITIES AND EXCHANGE COMMISSIONWashington, D.C. 20549 FORM10-Q ☒QUARTERLY REPORT PURSUANT TO SECTION13 OR 15(d)OF THE SECURITIES EXCHANGEACT OF 1934 For the quarterly period endedJune30, 2026 Indicate by check mark whether the registrant (1)has filed all reports required to be filed by Section13 or 15(d)of theSecurities Exchange Act of 1934 during the preceding 12months (or for such shorter period that the registrant wasrequired to file such reports), and (2)has been subject to such filing requirements for the past 90days. Yes☐No☒ Indicate by check mark whether the registrant has submitted electronically every Interactive Data File required to besubmitted pursuant to Rule405 of Regulation S-T (§232.405 of this chapter) during the preceding 12months (or forsuch shorter period that the registrant was required to submit such files). Yes☒No☐ Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer,smaller reporting company, or an emerging growth company. See the definitions of “large accelerated filer,”“accelerated filer,” “smaller reporting company,” and “emerging growth company” in Rule12b-2 of the Exchange Act. Large accelerated filerNon-accelerated filerEmerging growth company If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transitionperiod for complying with any new or revised financial accounting standards provided pursuant to Section13(a)of theExchange Act.☐ Indicate by check mark whether the registrant is a shell company (as defined in Rule12b-2 of the Exchange Act). Yes☐No☒ As of August 19, 2026, 37,914,805 shares of ClassA common stock, par value $0.01 per share and 5,805,639 shares ofClass B common stock, par value $0.01 per share, were issued and outstanding. Forward-Looking Statements This Quarterly Report contains statements that may constitute “forward-looking statements” for purposes of the federalsecurities laws. Forward-looking statements include, but are not limited to, statements regarding the Company and itsmanagement teams’ expectations, hopes, beliefs, intentions or strategies regarding the future. In addition, anystatements that refer to projections, forecasts or other characterizations of future events or circumstances, includingany underlying assumptions, are forward-looking statements. The words “anticipate,” “believe,” “continue,” “could,”“estimate,” “expect,” “intends,” “may,” “might,” “plan,” “possible,” “potential,” “predict,” “project,” “should,”“strive,” “will,” “would” and similar expressions may identify forward-looking statements, but the absence of thesewords does not mean that a statement is not forward-looking. Forward-looking statements in this Current Report mayinclude, for example, statements about: ●the failure to realize the benefits of the business combination and any transactions contemplated thereby;●the outcome of any potential legal proceedings that may be instituted against the Company or others;●the failure of the Company to mainta