Trigger-happy investors dumped stocks on Thursday, scared by the market's sudden fall through a key technical level brought on by more worries about Europe's sovereign debt troubles. Investors have been increasingly focused on Europe, and markets were cautious early as bond yields in Spain and Italy rose to levels viewed as unsustainable.

“There is no place to hide,” renowned currency and commodities trader Dennis Gartman said. “They took everything out to the woodshed and hit everything hard.”