Fell sharply

Stocks plunged, extending last week’s smackdown, with Standard & Poor’s downgrade of U.S. credit exacting a heavy toll on already troubled investor sentiment. Financials suffered worst. Tech stocks tumbled, highlighting a broad market retreat sparked by the downgrade. The tech sector’s heavyweights highlighted the slump with shares of Cisco, Hewlett-Packard, AMD, Dell, AAPL, Oracle and Google. Implied volatility surged well above the 40 level on huge volumes. But downside seen limited.