Amgen is trading at $407.71, with a -3.27% change; no confirmed same-day company-specific catalyst was found. - Teva received FDA approval for DEGEVMA, a biosimilar to Amgen’s Xgeva, on September 28; available reports do not establish it as the direct cause of Amgen’s October 1 decline. - Supplied market-index readings are nearly flat, offering no clear broad-market explanation.