A “network storm” hit communications systems and forced the New York Stock Exchange to halt trading in the crucial minutes before closing time on Wednesday.
In a brief statement, the NYSE blamed the shutdown at , four minutes before the scheduled close of business, on “a communications problem”. Trading did not resume until 9.30 the following morning.
But in a later interview with US financial news channel CNBC-TV, NYSE chief executive John Thain said,: “There was an error message that was created and then duplicated millions of times. It's called a network storm.”
“Both the primary routers and backup routers were overwhelmed.”
The exchange had since taken measures to prevent a repeat of the problem. “We separated the paths that the routers are on so that now, even if one router was overwhelmed by this type of network storm, the other one won't be”, he said.
Computer systems and communications at NYSE are run by the Securities Industry Automation Corporation, a subsidiary of NYSE and the American Stock Exchange, which also disseminates