USA Rare Earth Inc美股招股说明书(2026-01-26版)

PROSPECTUS SUPPLEMENT No. 7(to Prospectus dated July 21, 2025) This prospectus supplement updates, amends and supplements the prospectus dated July 21, 2025 (the “Prospectus”), which forms a part of our Registration Statement on Form S-1 (Registration No. 333-287410). Capitalized terms used in this prospectus supplement and not otherwise defined herein have the meanings specified in the Prospectus. This prospectus supplement is being filed to update, amend and supplement the information included in the Prospectus with the information contained in: ●our Current Report on Form 8-K filed with the SEC on January 26, 2026, excluding Item 2.02, Item 7.01, Exhibit 99.1, Exhibit 99.2 and Exhibit 99.3, which is set forthbelow. This prospectus supplement is not complete without the Prospectus. This prospectus supplement should be read in conjunction with the Prospectus, which is to be delivered withthis prospectus supplement, and is qualified by reference thereto, 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 is listed on the Nasdaq Stock Market LLC under the symbol “USAR”. On January 23, 2026, the closing price of our Common Stock was $24.77 per share. We are an “emerging growth company” and a “smaller reporting company” as such terms are defined under the federal securities laws and, as such, are subject to certain reducedpublic company reporting requirements. Investing in our securities involves a high degree of risk. You should review carefully the risks and uncertainties described under the heading “Risk Factors” of theProspectus, and under similar headings in any amendments or supplements to the Prospectus. Neither the SEC nor any state securities commission has approved or disapproved of these securities or determined if the Prospectus or this prospectus supplement istruthful or complete. Any representation to the contrary is a criminal offense. The date of this prospectus supplement is January 26, 2026. FORM 8-K CURRENT 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: ☐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: 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 theSecurities 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 financialaccounting standards provided pursuant to Section 13(a) of the Exchange Act.☐ Item 1.01. Entry into a Material Definitive Agreement. Private Placement Securities Purchase Agreement; On January 26, 2026, USA Rare Earth, Inc., a Delaware corporation (the “Company”), entered into a securities purchase agreement (the “Purchase Agreement”) with theseveral purchasers named therein (the “Purchasers”), for the private placement (the “Private Placement”) of 69,767,442 shares of the Company’s common stock, par value $0.0001per share (the “Shares”), for aggregate gross proceeds of approximately $1.5 billion, at a price per share of $21.50. Subject to the satisfaction of customary closing conditions, theCompany intends to close the Private Placement and issue the Shares on January 28, 2026. The Company intends to use the net proceeds from the Private Placement for generalcorporate purposes. The Purchase Agreement contains customary representations, warranties, covenants and agreements by the Company, indemnification obligations of the Company and thePurchasers, including for liabilities under the Securities Act of 1933, as amended (the “Securities Act”), and other obligations of the parties. The representations, warranties,covenants and agreements contained in the Purchase Agreement reflect negotiations between the parties to the Purchase Agreement and are not intended as statements of fact to berelied upon by stockholders, or any individual or other entity other than the parties. In particular, the representations, warranties, covenants and agreements in the PurchaseAgreement may be subject to limitations agreed by the parties, including having been modified or qualified by certain confidential disclosures that were made between the partiesi