美国稀土公司美股招股说明书(2025-11-06版)

USA Rare Earth, Inc. Thisprospectus supplement updates,amends and supplements the prospectus dated October 27,2025(the“Prospectus”), which forms a part of our Registration Statement on Form S-1 (Registration No. 333-290723). Capitalizedtermsused in this prospectus supplement and not otherwise defined herein have the meanings specified in theProspectus. This prospectus supplement is being filed to update, amend and supplement the information included in the Prospectuswith the information contained in: •our Quarterly Report on Form 10-Q filed with the SEC on November6, 2025, which is set forth below. This prospectus supplement is not complete without the Prospectus. This prospectus supplement should be read inconjunction with the Prospectus, which is to be delivered with this prospectus supplement, and is qualified by referencethereto, except to the extent that the information in this prospectus supplement updates or supersedes the informationcontained in the Prospectus. Please keep this prospectus supplement with your Prospectus for future reference. USA Rare Earth, Inc.’s Common Stock and Warrants are listed on the Nasdaq Stock Market LLC under the symbols“USAR” and “USARW,” respectively. On November5, 2025, the closing price of our Common Stock was $16.87 per shareand the closing price of our Warrants was $5.61 per Warrant. We are an “emerging growth company” and a “smaller reporting company” as such terms are defined under the federalsecurities laws and, as such, are subject to certain reduced public company reporting requirements. Investing in our securities involves a high degree of risk. You should review carefully the risks and uncertaintiesdescribed under the heading “Risk Factors” of the Prospectus, and under similar headings in any amendmentsor supplements to the Prospectus. Neither the SEC nor any state securities commission has approved or disapproved of these securities ordetermined if the Prospectus or this prospectus supplement is truthful or complete. Any representation to thecontrary is a criminal offense. The date of this prospectus supplement is November6, 2025. UNITED STATESSECURITIES AND EXCHANGE COMMISSIONWASHINGTON, D.C. 20549 FORM 10-Q ☑QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended September30, 2025 OR ☐TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from ____________ to __________ Commission File Number: 001-41711 USA Rare Earth, Inc.(Exact Name of Registrant as Specified in its Charter) 98-1720278 Delaware (I.R.S. Employer Identification No.) (State or Other Jurisdiction of Incorporation) 100 W. Airport Road, Stillwater, OK 74075(Address of Principal Executive Offices and Zip Code) (813) 867-6155(Registrant’s Telephone Number, Including Area Code) Securities registered pursuant to Section 12(b) of the Act: Indicate by check mark whether the registrant: (1)has filed all reports required to be filed by Section 13 or 15(d) of the SecuritiesExchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports),and (2)has been subject to such filing requirements for the past 90 days.Yes☑No☐ Indicate by check mark whether the registrant has submitted electronically every Interactive Data File required to be submitted pursuantto Rule405 of Regulation S-T (§232.405 of this chapter) during the preceding 12months (or for such shorter period that the registrantwas 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, a smaller reportingcompany, or an emerging growth company. See the definitions of “large accelerated filer,” “accelerated filer,” “smaller reportingcompany” and “emerging growth company” in Rule12b-2 of the Exchange Act. Smaller reporting company☑Emerging growth company☑ If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period forcomplying with any new or revised financial accounting standards provided pursuant to Section13(a) of the Exchange Act.☐ Indicate by check mark whether the registrant is a shell company (as defined in Exchange Act Rule12b-2).Yes☐No☑ As of October31, 2025, there were 132,638,561 shares of the registrant’s Common Stock outstanding, $0.0001 par value and1,602,257shares of 12% Series A Cumulative Convertible Preferred Stock, $0.0001 par value, . USA RARE EARTH, INC.Table of Contents Page No. PART IIOTHER INFORMATION FORWARD-LOOKING STATEMENTS ThisQuarterly Report on Form 10-Q contains forward-looking statements about us and our industry that involvesubstantial risks and uncertainties. All statements other than statements of historical facts contained in this QuarterlyReport on Form 10-Q, including statements regarding our future results of operation