Business Description

“Resources - Manufacturing Processes” of this Form 10-K. Item 3. Legal Proceedings None. Item 4. Mine Saf ety Disclosures Not applicable. 27 PART II Item 5. Market for Registrant’s Common Equity, Related Sto ckholder Matters and Issuer Purchases of Equity Securities Market Information Our outstanding common stock is traded under the ticker symbol “KALU” on the Nasdaq Global Select Market. Holders As of February 16, 2026, there were approximately 462 holders of record of our common stock. Stock Performance Graph The following graph compares the cumulative total shareholder return on our common stock with: (i) the Russell 2000 Index and (ii) the S&P SmallCap 600 Materials Index. We are a component of each of these indices. The graph assumes: (i) an initial investment of $100 as of December 31, 2020 and (ii) reinvestment of all dividends. The performance graph is not necessarily indicative of the future performance of our stock price. COMPARISON OF 5 YEAR CUMULATIVE TOTAL RETURN Among Kaiser Aluminum Corporation, the Russell 2000 Index and the S&P SmallCap 600 Materials Index 28 Issuer Repurchases of Equity Securities The following table provides information regarding our repurchases of our common shares during the quarter ended December 31, 2025: Equity Incentive Plans Stock Repurchase Plan Total Number of Shares Purchased 1 Average Price per Share Total Number of Shares Purchased 2 Average Price per Share Maximum Dollar Value of Shares that May Yet Be Purchased Under the Program (millions) 2 October 1, 2025 - October 31, 2025 444 $ 93.12 — $ — $ 93.1 November 1, 2025 - November 30, 2025 475 95.53 — — 93.1 December 1, 2025 - December 31, 2025 649 115.10 — — 93.1 Total 1,568 $ 102.95 — $ — n/a 1. Under our equity incentive plan, we may elect to withhold common shares to satisfy minimum statutory tax withholding obligations arising from the recognition of income and the vesting of restricted stock, restricted stock units, and performance shares. When we withhold these shares, we are required to remit to the appropriate taxing authorities the market price of the shares withheld by us on the date of withholding. The withholding of common shares by us could be deemed a purchase of such common shares. 2. In September 2018, our Board of Directors authorized us to repurchase an indeterminate number of shares of our common stock at an aggregate market value of up to $100.0 million. At December 31, 2025, $93.1 million remained available to repurchase our common shares pursuant to the stock repurchase program. The September 2018 authorization does not have an expiration date. Item 6. [Re served] 29 Item 7. Management’s Discussion and Analysis of Financial Condition and Results of Operations The following discussion and analysis of our financial condition and results of operations should be read in conjunction with our consolidated financial statements and related notes included in Item 8. “Financial Statements and Supplementary Data” of this Form 10-K. For a detailed discussion of items impacting the year ended December 31, 2023, as well as a year‑to‑year comparison of our financial position and results of operations for the years ended December 31, 2024 and December 31, 2023, refer to Part II, Item 7. “Management’s Discussion and Analysis” of our Annual Report on Form 10-K for the year ended December 31, 2024 filed with the SEC on February 20, 2025. Basis of Presentation Effective January 1, 2025, we changed our inventory valuation methodology from LIFO to WAC. The effects of this change in accounting principle have been retrospectively applied to all periods presented with a cumulative effect adjustment reflected in the January 1, 2023 beginning retained earnings. See Note 18 of our consolidated financial statements included in Item 8. “Financial Statements and Supplementary Data” of this Form 10-K for further information. Prior period information provided in this Management’s Discussion and Analysis has been updated to reflect the retrospective application of the change in accounting principle. Non-GAAP Financial Measures This information contains certain non-GAAP financial measures. A non-GAAP financial measure is defined as a numerical measure of a company’s financial performance that excludes or includes amounts so as to be different than the most directly comparable measure calculated and presented in accordance with US GAAP in the statements of income, balance sheets, or statements of cash flows of the company.…