144 0001980271 XXXXXXXX LIVE 0000949157 CENTURY ALUMINUM CO 001-34474 1 SOUTH WACKER DRIVE SUITE 1000 CHICAGO IL 60606 3126963101 Trpkovski Peter A Officer common Wells Fargo Clearing Services

1 North Jefferson Avenue St. Louis MO 63103

16739 844539.80 98974047 03/25/2026 Nasdaq Common 12/31/2023 Compensation Issuer N 2434 12/31/2023 N/A Common 02/12/2024 Compensation Issuer N 6069 02/12/2024 N/A Common 12/31/2024 Compensation Issuer N 3457 12/31/2024 N/A Common 02/01/2025 Compensation Issuer N 4779 02/01/2025 N/A Y shares were sold in account for Peter Alex Trpkovski Trust, Peter Trpkovski as trustee. 03/25/2026 Peter A Trpkovski