Sales of existing U.S. homes rose to the highest level in eight years, according to the National Association of Realtors, but that may be the peak for the year. One real estate brokerage claims consumer demand for housing took a sharp turn for the worse in June, as potential buyers balked at higher home prices.

"People look at houses and don't pull the trigger," said Glenn Kelman, CEO of brokerage Redfin, which released a new demand index on Thursday. "We know that the number of people writing offers has been declining for 4½ weeks, and based on that data we make a forecast."