144 0001323719 XXXXXXXX LIVE 0000811596 Kaiser Aluminum 001-09447 1550 West McEwen Drive Suite 500 Franklin TN 37067 (629) 252-7040 Blain Tiffany Officer common UBS Financial Services Inc

1000 Harbor Blvd 3rd Floor Weehawken NJ 07086

7111 797415.9 16210443 03/23/2026 NASDAQ common 03/05/2026 RSU Kaiser Aluminum N 1848 03/23/2026 cash common 03/05/2026 PSA Kaiser Aluminum N 4069 03/23/2026 cash common 03/05/2026 RSU Kaiser Aluminum N 1194 03/23/2026 cash N Kaiser Aluminum

1550 West McEwen Drive Suite 500 Franklin TN 37067

common 02/23/2026 15231 1875645 03/23/2026 /s/Mijo Suric, for UBS Financial Services Inc, as attorney-in-fact for Blain Tiffany