Carpenter Technology Corp. said its newly appointed CEO, Brian Malloy, 59, died suddenly on Friday. The 137-year-old Pennsylvania specialty stainless-steel alloy maker, which serves medical, aerospace and defense customers, is valued at about $3 billion. Shares slid about 4% on Monday to roughly $580 after the announcement. The abrupt leadership change is a short-term shock to governance stability at the publicly traded company.