BY THE NUMBERS: Tuesday was one of the worst days on Wall Street this year. The Dow Jones industrial average shed 243 points. That's not far from its biggest one-day loss this year on June 1, when it shed 274 points.
WHAT WENT WRONG: Investors were spooked after companies like Xerox, 3M and DuPont reported lower revenue for the third quarter, a sign that the overall economy is far from healed.
LOOKING AHEAD: So far this earnings season, 29 companies in the S&P 500 have updated predictions for fourth-quarter results, according to S&P Capital IQ. Of those, 23 lowered their forecasts, and six kept them roughly the same. None said it was expecting things to be better than it already predicted.