NYSE Halts Trading

The NYSE Group, which includes the New York Stock Exchange, has suspended trading in all securities due to technical difficulties, the unit of Intercontinental Exchange Inc (ICE.N) said on Wednesday.

The cause for the shutdown was not immediately apparent. The NYSE said in a statement that it had experienced a "technical issue" that it was working to resolve.

The stocks continue to trade on other exchanges, such as those run by Nasdaq OMX Group (NDAQ.O) and BATS Global Markets.

Before the market opened at 9:30 this morning, the NYSE sent out notices to members saying that it was experiencing a "gateway connectivity issue," according to Joe Saluzzi, co-founder of Themis Trading, which trades stocks on behalf of major companies and institutions.

The NYSE did note that there had been a small technical issue at 10:37 A.M. EST, but said that it had been resolved. Then, at 11:51 A.M. EST, the NYSE suspended trading on all symbols — in other words, all companies on its exchange.

The issues at NYSE came on the same day that computer problems led United Airlines to ground all its flights for about two hours.

The U.S. Department of Homeland Security said there were no signs" that the problems at NYSE and United Airlines stemmed from "malicious activity," CNN reported.

There will be a bigger problem, however, if the technical problem continues until the close of trading. The opening and closing of the trading day are important moments for the determination of stock prices, when more people and computers rush to buy and sell stocks. Very high volume could create bottlenecks at other stock exchanges.