Updated from 3:38 p.m. EST
The widely followed
Nasdaq Composite Index
and other market information from the Nasdaq stock market stopped flowing for nearly three hours Friday because of a broken communication line from one of Nasdaq's mainframe computers.
The outage, which began around 11:30 a.m. EST, stopped the flow of Nasdaq stock indexes to companies that distribute the data.
In addition, transaction data for stocks with ticker symbols beginning with "A" through "J" stopped flowing to market professionals who trade using the exchange's Nasdaq-2 terminals.
The company said the problem had been solved by about 1:30 p.m., but a backlog of infomation prevented the data from updating until about 2:30 p.m.
Nasdaq said that throughout the episode, trading had not been significantly affected because market professionals were able to see live prices through other data vendors, including
Bridge Information Services
"Information on last-sale prices were still being disseminated to market data vendors, so the trading public had access at all times," said Wayne Lee, a Nasdaq spokesman.
To most market watchers, the Nasdaq Composite appeared to be down only about 13 points through the episode. When the index began updating again, it was roughly 85 points lower.
The index kept falling, and closed down 137.18, or 3%, at 4411.74.
Separately, investors who use the San Francisco-based online broker
( SCH) were unable to trade or access their account information for a
brief period Friday.
"Automated Internet and telephone account access was not available for about a half-hour," said Greg Gable, a Schwab spokesman. He said the outage occurred around 1:45 p.m. EST, and trading didn't resume until a backup system was started up around 2:15 p.m. He later acknowledged that Schwab was also having "sporadic access problems with the backup system."
Gable said the cause of the outage was an internal computer software problem.