Technical glitches plague Wall Street

Dow Jones says problem with DJIA reporting made big decline seem more dramatic; NYSE trading interrupted due to intermittent technical problems.

By Jessica Dickler, CNNMoney.com staff writer

NEW YORK (CNNMoney.com) -- As the Dow Jones industrial average suffered its biggest one-day point loss in 5-1/2 years Tuesday afternoon, traders were blind to the severity of the fall due to technical problems.

Dow Jones (Charts) said that for about an hour it experienced difficulty with its system for reporting the industrial average's activity.

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"Around 2:00 pm today the market's extraordinarily heavy trading volume caused a delay in the Dow Jones data systems and as a result, the calculation of the Dow Jones Industrial Average temporarily lagged behind the market decline and as we identified the problem we decided to switch over to a back-up system and the result was a rapid catch-up in the published value of the Dow Jones Industrial Average," explained a Dow Jones spokeswoman.

When the back up system was activated around 3:00 pm, the delay was eliminated and the numbers on the big board caught up immediately with market activity.

At 3:02 pm, the Dow reflected a 160-point drop. Over the course of several minutes the blue chip barometer sank over 300 points as traders reacted to the newly available data.

"The drop lag that occurred in a minute should should have happened over a period of 20, 30 or 40 minutes," the spokeswoman said.

However, "investment products like futures contracts, exchange rate funds or mutual funds that use the index as an underline were not affected," the spokeswoman noted.

Separately, the New York Stock Exchange (Charts) said intermittent systems problems disrupted some trading Tuesday afternoon.

"Trading towards the end of the day was interrupted due to an intermittent technical problem and that problem is being assessed as we speak," an NYSE spokesman said.

It is unclear whether the problems are related, the spokesman said.

The Dow tumbled 416 points by the closing bell, notching its worst point decline since September 17, 2001, the first trading day after the September 11th disaster. On that day, the Dow dropped 684 points.

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Most stock quote data provided by BATS. Market indices are shown in real time, except for the DJIA, which is delayed by two minutes. All times are ET. Disclaimer.

Morningstar: © 2014 Morningstar, Inc. All Rights Reserved.

Factset: FactSet Research Systems Inc. 2014. All rights reserved.

Chicago Mercantile Association: Certain market data is the property of Chicago Mercantile Exchange Inc. and its licensors. All rights reserved.

Dow Jones: The Dow Jones branded indices are proprietary to and are calculated, distributed and marketed by DJI Opco, a subsidiary of S&P Dow Jones Indices LLC and have been licensed for use to S&P Opco, LLC and CNN. Standard & Poor's and S&P are registered trademarks of Standard & Poor’s Financial Services LLC and Dow Jones is a registered trademark of Dow Jones Trademark Holdings LLC. All content of the Dow Jones branded indices © S&P Dow Jones Indices LLC 2014 and/or its affiliates.

Most stock quote data provided by BATS. Market indices are shown in real time, except for the DJIA, which is delayed by two minutes. All times are ET. Disclaimer.

Morningstar: © 2014 Morningstar, Inc. All Rights Reserved.

Factset: FactSet Research Systems Inc. 2014. All rights reserved.

Chicago Mercantile Association: Certain market data is the property of Chicago Mercantile Exchange Inc. and its licensors. All rights reserved.

Dow Jones: The Dow Jones branded indices are proprietary to and are calculated, distributed and marketed by DJI Opco, a subsidiary of S&P Dow Jones Indices LLC and have been licensed for use to S&P Opco, LLC and CNN. Standard & Poor's and S&P are registered trademarks of Standard & Poor’s Financial Services LLC and Dow Jones is a registered trademark of Dow Jones Trademark Holdings LLC. All content of the Dow Jones branded indices © S&P Dow Jones Indices LLC 2014 and/or its affiliates.