Major stock indexes are opening lower.

The Dow Jones industrial average is down four points to 13,122.

The broader Standard & Poor's 500 index is down two to 1,407, and the Nasdaq composite index is down four to 3,068.

The price of a house increased in all major U.S. cities in June, according to the Standard & Poor's/Case-Shiller home price index. The report was the latest sign that the housing market has been gaining strength.

Crude oil crept above $96 a barrel, as Tropical Storm Isaac moved through the Gulf of Mexico. The National Hurricane Center in Miami predicted Isaac would move to hurricane status. Roughly one-quarter of the country's oil is produced in the Gulf. As of Monday afternoon, about 80 percent of Gulf oil production had been suspended.