Nasdaq said on Thursday it was halting trading in all Nasdaq-listed shares until further notice due to a problem distributing stock price quotes.
All traffic through Nasdaq stopped at 12:14 p.m. EDT (1614 GMT), the exchange said on its website.
"I would not want to speculate other than to say this is huge, everything is halted in the market," said Sal Arnuk, co-manager of trading at Themis Trading in Chatham, New Jersey,
Options trading was also halted, the exchange said.
Nasdaq was not immediately available for comment.
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