Federal Reserve Chairman Ben Bernanke's comments that the economy will continue sliding sent the markets tumbling during the midday with the Dow dropping 94 points to 12,458. Nasdaq tumbled 26 points to 2348.

On the upside

Strong demand lifted fourth quarter earnings for Amkor Technology (Nasdaq: AMKR) to beat expectations by a wide margin.

Although Equinix (Nasdaq: EQIX) swung to a fourth quarter loss due to soaring expenses, the data center provider lifted its 2008 revenue guidance.

Advanced Medical Optics (NYSE: EYE) blamed a contact lens solution recall for widening fourth quarter losses and lowered its revenue outlook for 2008 but the guidance was within analyst estimates.

On the downside

Deutsche Securities downgraded Allscripts (Nasdaq: MDRX) after the clinical software provider reported fourth quarter revenue below estimates.

Netgear (Nasdaq: NTGR) blamed higher costs for fourth quarter earnings that slipped to fall short of estimates and forecast first quarter results below expectations.

Liz Claiborne (NYSE: LIZ) warned that fourth quarter earnings will fall short of estimates due to weak sales.

In the broad market, declining issues outpaced advancers by a margin of more than 5 to 2 on the NYSE and by more than 2 to 1 on Nasdaq. The Russell 2000 which tracks small cap stocks tumbled 12 points to 710.