Vanguard Portfolio Management LLC filed an amended beneficial ownership statement with the SEC on October 30, 2026, disclosing a 9.52% stake in Kaiser Aluminum Corp common stock as of the September 30, 2026 triggering event date.

Key Highlights

  • Aggregate beneficial ownership: Vanguard Portfolio Management reported holding 1,556,558 shares of Kaiser Aluminum Corp common stock.
  • Percent of class: The reported position represents 9.52% of Kaiser Aluminum's outstanding common stock.
  • Sole dispositive power: Vanguard Portfolio Management holds sole power to dispose of all 1,556,558 shares.
  • Sole voting power: Only 16,089 shares carry sole voting power; shared voting power is reported as zero.
  • Event date: The filing was triggered by a September 30, 2026 ownership event, with the statement signed October 30, 2026.
  • Amendment: This is Amendment No. 1 to a prior beneficial ownership statement for the same issuer and share class.

Vanguard's Reported Position in Kaiser Aluminum Common Stock

According to the filing, Vanguard Portfolio Management LLC, organized in Pennsylvania and headquartered at 100 Vanguard Blvd, Malvern, PA 19355, disclosed beneficial ownership of 1,556,558 shares of Kaiser Aluminum Corp (NASDAQ:KALU) common stock. The filing identifies Kaiser Aluminum Corp's principal executive offices as located at 1550 W Mcewen Dr, Suite 500, Franklin, TN 37067. Kaiser Aluminum is a manufacturer of semi-fabricated specialty aluminum products serving end markets including aerospace, automotive, and general engineering applications.

The filing indicates that sole dispositive power covers the full 1,556,558-share position, while sole voting power applies to only 16,089 shares. Shared voting power and shared dispositive power are each reported as zero. As the filing explains, the statement reflects securities beneficially owned by Vanguard Portfolio Management LLC and affiliated entities, specifically Vanguard Fiduciary Trust Company and Vanguard Global Advisers, LLC. It also notes that the reported holdings include securities held by Vanguard funds, or sleeves thereof, over which Vanguard Portfolio Management LLC exercises dispositive power, as well as securities held by clients over which the named affiliates exercise dispositive and/or voting power.

The filing further states that Vanguard Portfolio Management, including registered investment companies and other managed accounts, "have the right to receive or the power to direct the receipt of dividends from, or the proceeds from the sale of, the securities reported herein," and that no single other person's interest in the reported securities exceeds 5%. The statement was signed by My Trieu-Gatt, identified as Authorized Signatory, Head of Global Fund Administration, on October 30, 2026.

What Was Disclosed

Vanguard Portfolio Management LLC filed Amendment No. 1 to its beneficial ownership statement covering 1,556,558 shares of Kaiser Aluminum Corp common stock, equating to 9.52% of the class, with the triggering event dated September 30, 2026.