Wall Street back in business

New York City Mayor Michael Bloomberg (center) presided over a trouble-free opening bell at the New York Stock Exchange Wednesday.

NEW YORK — Wall Street is back in business.

Traffic was snarled, streets were flooded, subways were out of commission and power was out in many parts of New York City, but the stock exchange at 11 Wall St. opened trading without a hitch Wednesday after an historic two-day shutdown, courtesy of Hurricane Sandy.

Stocks closed mix.

New York City Mayor Michael Bloomberg rang the opening bell at 9:30 a.m., right on schedule, then gave a thumbs-up as traders cheered from the trading floor below.

“It’s good for the city, good for country, it’s good for everyone to get back to work,” the mayor told CNBC moments later while leaving the exchange building in lower Manhattan.

The last time the New York Stock Exchange closed for two consecutive days because of weather was during the Blizzard of 1888 124 years ago.

The company that operates the exchange, NYSE Euronext, said the trading floor Wednesday was running on backup generators since power is out in large parts of downtown Manhattan.

“It’s been very smooth,” Duncan Niederauer, CEO of NYSE Euronext, told CNBC from the exchange floor shortly after the opening bell. “The market-making community is more than staffed enough to be open.”

The opening followed days of scrambling by NYSE officials to make sure power, telecom connections and computers would be ready Wednesday morning.

The company had booked hotel rooms nearby for traders.

Many workers on the floor use the subways to get downtown, but Sandy left the system with its worst damage in its 108-year history.

New York’s governor, Andrew Cuomo, said limited subway service will resume in New York City today.

The Dow Jones industrial average gave up an early gain on the first day back and closed down 10.75 points at 13,096.46.

The S&P 500 edged up 0.22 to 1,412.16. The Nasdaq lost 10.72 to end at 2,977.23.

Home Depot and Lowe’s rose as investors anticipated more business for the home improvement chains as people made repairs in the aftermath of the devastating storm.