With the declines yesterday, U.S. markets are now in an official correction. Just to get the terminology straight, a “correction” means a 10-percent decline, while a "bear market" indicates a 20-percent decline. As of the close yesterday, the Dow was down 10.3 percent, and the S&P 500 was down 10.1 percent. The decline really accelerated at the end of the day—bringing the indices into official correction territory.