Stardust Power Inc. American Stock Offering Prospectus (Version as of May 20, 2026)

STARDUST POWER INC. Up to 2,000,000 Shares of Common Stock This prospectus supplement supplements the prospectus dated February 17, 2026 (the “Prospectus”), which forms a part ofour registration statement on Form S-1 (No. 333-293405). This prospectus supplement is being filed to update and supplement theinformation in the Prospectus with the information contained in our Form 10-Q for the fiscal quarter ended March 31, 2026 filed withthe Securities and Exchange Commission (the “SEC”) on May 14, 2026 (the “Form 10-Q”). Accordingly, we have attached the Form The Prospectus relates to the offer and resale of up to 2,000,000 shares of our common stock, $0.0001 per share (the“Common Stock”), by B. Riley Principal Capital II, LLC (the “Selling Stockholder”). The shares included in this Prospectus consistof shares of Common Stock that we have issued or that we may, in our discretion, elect to issue and sell to the Selling Stockholder,from time to time after the date of this Prospectus, pursuant to a Common Stock Purchase Agreement we entered into with the SellingStockholder on February 12, 2026 (the “Purchase Agreement”), in which the Selling Stockholder has committed to purchase from us, Our Common Stock is listed on The Nasdaq Capital Market under the symbols “SDST”. On May 18, 2026, the last reportedsales price of our Common Stock was $2.11 per share. We are an “emerging growth company” and a “smaller reporting company” as defined under U.S. federal securities laws and,as such, have elected to comply with reduced public company reporting requirements. The Prospectus and this prospectus supplementcomply with the requirements that apply to an issuer that is an emerging growth company and a smaller reporting company. Thisprospectus supplement updates and supplements the information in the Prospectus and is not complete without, and may not be Investing in our securities involves a high degree of risk. You should review carefully the risks and uncertaintiesdescribed in the section titled “Risk Factors” beginning on page 15 of the Prospectus, and under similar headings in anyamendments or supplements to the Prospectus. Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved ofthese securities, or passed upon the accuracy or adequacy of the Prospectus or this prospectus supplement. Any representation The date of this prospectus supplement is May 20, 2026. UNITED STATESSECURITIES AND EXCHANGE COMMISSION FORM 10-Q ☒QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Commission File Number: 001-39875 STARDUST POWER INC. (Exact name of registrant as specified in its charter) Not applicable 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), Indicate by check mark whether the registrant has submitted electronically every Interactive Data File required to be submitted andpursuant to Rule 405 of Regulation S-T (§232.405 of this chapter) during the preceding 12 months (or for such shorter period that the Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smallerreporting company, or an emerging growth company. See definitions of “large accelerated filer,” “accelerated filer,” “smaller reporting 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 Section 13(a) of the Exchange Act.☐ Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act). Yes☐No☒ As of May 13, 2026, there were 10,579,727 shares of common stock, par value $0.0001 per share, issued and outstanding. Table of Contents PagePART I – FINANCIAL INFORMATION1Item 1.Financial Statements1Condensed Consolidated Balance Sheets as of March 31, 2026 (unaudited) and December 31, 20251Condensed Consolidated Statements of Operations for the three months ended March 31, 2026, and 2025(unaudited)2Condensed Consolidated Statements of Changes in Stockholders’ Deficit for the three months ended March 31,2026, and 2025 (unaudited)3Condensed Consolidated Statements of Cash Flows for the three months ended March 31, 2026, and 2025(unaudited)4Notes to Condensed Consolidated Financial Statements (unaudited)5Item 2.Management’s Discussion and Analysis of Financial Condition and Results of Operations27Item 3.Quantitative and Qualitative Disclosures About Market Risk42Item 4.Controls and Procedures44PART II – OTHER INFORMATION45Item 1.Legal Proceedings45Item 1A.Risk Factors45Item 2.Unregistered Sales of Equity Securities and Use of Proceeds45Item 3.Defaults Upon Senior Securities4