The New York Stock Exchange and other major U.S. exchanges opened for trading as usual Monday. The Securities Industry and Financial Markets Association, which represents Wall Street banks, said it expects the bond market to operate normally.

The Dow Jones industrial average rose 170 points, or 1.5 percent, to 11,455 in morning trading.

The Standard & Poor's 500 index rose up 20, or 1.6 percent, to 1,197. The Nasdaq composite index rose 48, or 1.9 percent, to 2,529.

Greek stocks jumped 15 percent after the country's second- and third-largest lenders agreed to combine, creating the country's largest bank. Greece's government and central bank have been urging banks to merge, saying it would help them survive the country's debt crisis.

The S&P 500 has plunged about 11 percent since July 21, in part because of worries about Europe's escalating debt problems. Greece has narrowly avoided bankruptcy twice thanks to emergency loans from the International Monetary Fund and its European neighbors.

Bank of America Corp. rose 4.4 percent after the bank said it would sell half of its stake in China Construction Bank Corp. to raise capital and comply with new banking regulations. Billionaire Warren Buffett said last week that he would invest $5 billion in the bank, giving the troubled lender a badly needed boost of confidence. Bank of America, the nation's largest bank, has lost 35 percent of its value over the past year as investors worry that the bank's liabilities from soured mortgages will get worse and that it will have to sell large amounts of stock to raise capital.

An increase in consumer spending also sent stocks higher. The government reported that spending rose 0.8 percent in July, after Americans cut their spending for the first time in about two years in June.

Volume was expected to be weak as transit disruptions made it difficult for Wall Street employees to get to work. Flooding and downed trees obstructed tracks throughout the commuter rail systems that bring workers in from the Connecticut, New York and New Jersey suburbs.

Partial subway service in New York restarted at 6 a.m. Transit officials said service would be less frequent than normal and that commuters should expect longer waits and more crowded trains.

Many traders were on still on summer vacation a week before the Labor Day holiday.

"I think it will be a relatively quiet day from a volume perspective," said Eric Noll, executive vice president of transaction services at Nasdaq OMX Group Inc. "It's sometimes easy to forget in a hurricane that lots and lots of people are on vacation or planning to go on vacation."

Many investment banks that have offices in Lower Manhattan said they would operate as usual, even if employees had to work from home or find alternative ways to get to the office. Goldman Sachs Group Inc. and Citigroup Inc. both said their buildings were largely unaffected by the storm.