NEW YORK — New hope for the economy just gave the stock market its best July in 20 years.

Investors placed big bets over the last month that the profit machine at U.S. companies will continue to rev higher and that the longest recession since World War II is finally easing its grip. If that turns out to be wrong, the huge gains of July mean there will be an even bigger price to pay if companies don't deliver.

The Dow surged 725 points or 8.6 percent for the month, with most of the gains arriving in bursts in the final 15 days. The extraordinary run shaped July into the best month for the blue chips since October 2002 and the best July since 1989.