NEW YORK (CNNMoney) -- The New York Stock Exchange suspended trading 11:32 a.m ET Wednesday morning. Earlier United and The Wall Street Journal were hit by network problems.
In a brief announcement, the exchange said it was experiencing a technical issue:
"We're currently experiencing a technical issue that we're working to resolve as quickly as possible. We will be providing further updates as soon as we can, and are doing our utmost to produce a swift resolution, communicate thoroughly and transparently, and ensure a timely and orderly market re-open," the NYSE said.
The Department of Homeland Security told CNN that there is "no sign of malicious activity" at the NYSE or with the earlier outage experienced by United Airlines.
It appears that all other exchanges, including the Nasdaq, are still operating. That means investors can still trade, just not on the NYSE.
The Wall Street Journal's homepage stopped functioning around the same time that the NYSE went down. The Journal was able to restore a limited homepage by 12:18 pm ET with the message "WSJ.com is having technical difficulties. The full site will return shortly."
United Airlines' computer system malfunctioned Wednesday morning, but it was back up by the time NYSE had problems.
Earlier in the day Wednesday, about 200 NYSE stock symbols halted trading due to a technology glitch, including Macy's and Kate Spade, but that seemed to have cleared. The exchange says there is more information to come.
"They've been having problems all day. They seemed to have rectified it earlier and then it happened again. Now they shut it all down," said Joe Saluzzi, co-head of trading at Themis Trading and author of Broken Markets.
U.S. markets were already down Wednesday. The Dow was down 175 points (about 1%) around the time of the halt. The losses have deepened.
The uncertainty comes as investors were already concerned about a huge sell-off in Chinese stocks and the ongoing crisis in Greece.
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