SECURITIES AND EXCHANGE COMMISSION ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year endedDecember 31, 2024OR TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Indicate by check mark if the registrant is a well-known seasoned issuer, as defined in Rule 405 of the Securities Act.YesoNox Indicate by check mark if the registrant is not required to file reports pursuant to Section 13 or Section 15(d) of the Act. YesoNox Indicate by check mark whether the registrant: (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during thepreceding 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 90days.YesxNoo Indicate by check mark whether the Registrant has submitted electronically; every Interactive Data File required to be submitted pursuant to Rule 405 of Regulation S-T(§232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit such files).YesxNoo Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smaller reporting company, or an emerginggrowth company. See the definitions of “large accelerated filer,” “accelerated filer,” “smaller reporting company,” and “emerging growth company” in Rule 12b-2 of theExchange Act. Emerging growth companyo 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 revisedfinancial accounting standards provided pursuant to Section 13(a) of the Exchange Act.o Indicate by check mark whether the registrant has filed a report on and attestation to its management’s assessment of the effectiveness of its internal control overfinancial reporting under Section 404(b) of the Sarbanes-Oxley Act (15 U.S.C. 7262(b)) by the registered public accounting firm that prepared or issued its audit report.x If securities are registered pursuant to Section 12(b) of the Act, indicate by check mark whether the financial statements of the registrant included in the filing reflect thecorrection of an error to previously issued financial statements.o Indicate by check mark whether any of those error corrections are restatements that required a recovery analysis of incentive-based compensation received by any of theregistrant’s executive officers during the relevant recovery period pursuant to §240.10D-1(b).o Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act). YesoNox Based on the closing price of $1.51 per share as reported on the Nasdaq Stock Market, the aggregate market value of the registrant’s voting and non-voting commonstock held by non-affiliates of the registrant on June 30, 2024 (the last business day of the registrant’s most recently completed second fiscal quarter) was approximately$121million. Shares of common stock held by each executive officer and director and by each shareholder affiliated with a director or an executive officer have beenexcluded from this calculation because such persons may be deemed to be affiliates. This determination of affiliate status is not necessarily a conclusive determinationfor other purposes. The number of outstanding shares of the registrant’s common stock as of February18, 2025 was120,063,981. This includes 18,312,208 shares ofcommon stock held by Homeowners of America, the registrant’s affiliate. The information required by Part III (Items 10, 11, 12, 13 and 14) of this Annual Report on Form 10-K is incorporated by reference from the registrant’s definitive proxystatement for its 2025 annual meeting to be filed with the Securities and Exchange Commission pursuant to Regulation 14A. Table of Contents TABLE OF CONTENTS PART I Item 1. BusinessItem 1A. Risk FactorsItem 1B. Unresolved Staff CommentsItem 1C. CybersecurityItem 2. PropertiesItem 3. Legal ProceedingsItem 4. Mine Safety Disclosures PART II Item 5. Market for Registrant’s Common Equity, Related Stockholder Matters and Issuer Purchases of Equity Securities47Item 6. Reserved48Item 7. Management’s Discussion and Analysis of Financial Condition and Results of Operations49Item 7A. Quantitative and Qualitative Disclosures About Market Risk63Item 8. Financial Statements and Supplementary Data65Item 9. Changes in and Disagreements with Accountants on Accounting and Financial Disclosure119Item 9A. Controls and Procedures119Item 9B. Other Information122Item 9C. Disclosure Regarding Foreign Jurisdictions that Prevent Inspections122 PART III Item 10. Directors, Executive Officers and Corporate Governance123Item 11. Executive Compensation123Item 12. Security Ownership of Certain Beneficial Owners and Management and Related Stockholder Matters12