Western Digital is trading at $418.00 (-5.35%) amid renewed concern that Toshiba’s planned HDD capacity expansion could pressure industry pricing and margins. - Coverage identifies the potential supply impact as the main near-term focus after a sharp rebound on October 5. - Seagate and Toshiba’s contest for TDK’s HDD-head business is also in focus, but reporting does not establish it as the direct cause of the decline. - Major indices are up modestly, so broad-market weakness does not explain the move.