144 0001302874 XXXXXXXX LIVE 0000106040 Western Digital Corporation 001-08703 5601 Great Oaks Parkway San Jose CA 95119 408-717-6000 Martin I Cole Affiliate Common J.P. Morgan Securities LLC

390 Madison Avenue - 6th Floor New York NY 10017

16000 2434880 341899281 11/05/2025 Nasdaq Common 11/01/2017 Compensation Issuer N 4187 11/01/2017 Compensation Common 11/03/2015 Compensation Issuer N 2100 11/03/2015 Compensation Common 11/15/2024 Compensation Issuer N 5213 11/15/2024 Compensation Common 11/15/2021 Compensation Issuer N 4500 11/15/2021 Compensation Y The shares represented on this filing are being sold by the Martin I Cole Revocable Trust, Martin I Cole as Trustee 11/05/2025 /s/ J.P. Morgan Securities LLC as agent and attorney-in-fact for Martin I Cole