Kaiser Aluminum Corporation director Richard Grimley sold 1,524 shares of common stock for approximately $261,000, according to an SEC Form 4 filing. The transaction was executed at a weighted average price of $171.52 per share, slightly below the 29 April 2026 closing price of $172.52. The sale represented 25% of Grimley's direct holdings, reducing his position from 6,102 to 4,578 shares. All shares were sold from direct ownership, with no indirect holdings, trusts or options involved. Kaiser Aluminum manufactures semi-fabricated specialty aluminium mill products for aerospace, packaging, automotive and general engineering applications. The company reported revenue of $3.7 billion and net income of $153.4 million for the trailing twelve months.

Kaiser Aluminum Corporation reported strong Q1 2026 results on 22 April, with non-GAAP earnings per share of $3.74, beating estimates by $1.78. Revenues rose 41.6% year-over-year to $1.1 billion, exceeding estimates by $100.1 million. The semi-fabricated specialty aluminium products manufacturer expects 10% to 15% improvement in conversion revenue and 20% to 30% growth in adjusted EBITDA for full-year 2026. Despite the strong performance and tailwinds from tariffs, CNBC's Jim Cramer declined to recommend the stock during Mad Money's lightning round, citing its sharp recent price appreciation. "I can't recommend it. It's just straight up," Cramer told a caller asking about the company.

Kaiser Aluminum Corporation has raised $120 million in a Series C round led by Ribbit Capital, valuing the company at $1.45 billion. Sequoia and Kleiner Perkins participated, with Emerson Collective joining as a new backer. The pre-revenue company is developing "Mathematical Superintelligence", an AI system focused on advanced reasoning that claims to eliminate hallucinations by requiring outputs in Lean4 programming language. Its flagship model, Aristotle, achieved top-level performance at the International Mathematical Olympiad in July alongside Google and OpenAI. Founded in 2023, Harmonic has raised $295 million across three funding rounds in 14 months. The company currently offers Aristotle via a free API to mathematicians and researchers, and plans future commercialisation in safety-critical sectors like aerospace and finance.