U.S. stocks declined on Wednesday, with Wall Street retreating after a sixth day of gains for the S&P 500 and Nasdaq, after data had new home sales declining in March and companies including Boeing and AT&T reported quarterly results.

"We've rallied for six consecutive days. You know what you're supposed to do on the seventh," said Elliot Spar, market strategist at Stifel, Nicolaus & Co.