Investors will now most likely focus on macroeconomic factors like the economy. On Friday, the monthly unemployment data as well as other delayed government economic reports will be released, which may have an impact on the presidential election. In an indication that the economy could be losing some of its steam, the Dow was down 2.5 percent for the month of October, while the Nasdaq was off 4.5 percent and the S.& P. was down 2 percent.

For their part, exchange officials were pleased with the trading on Wednesday. Lawrence E. Leibowitz, NYSE Euronext’s chief operating officer, wandered about the floor, checking on operations.

“There have been very few, very isolated problems,” Mr. Leibowitz said. He pointed to blank monitors that were shut off because the data provider, Thomson Reuters, was delivering incorrect market data.

“If that’s the worst of our problems,” he added, “we’re in good shape.”

The specialists who handle market orders for the Big Board were back as well, darting about the trading pits in their usual colored jackets. Many gathered outside — not to smoke, but to try to grab a cellphone signal that was impossible to find inside. But getting to the relative calm of Wednesday’s open took significant work. For days, exchange officials traded lengthy conference calls with trading firms, regulators, and city and state officials about how best to resume trading in the nation’s financial heart.