Dow Jones Indexes plans to extend the real-time calculation of the Dow Jones industrial average to 13 hours a day, with the first 6.5 hours being "indicative of the indexs value prior to the opening of the U.S. stock market. The change, to take effect in September, will give investors an indication of the DJIAs level based on actual trades of the 30 biggest U.S. stocks on the electronic trading platform of Deutsche Börse, the German stock exchange.
While real-time updating of the DJIA will begin at 3 a.m. EDT daily, the "official DJIA calculation will take over as usual at 9:30 a.m. EDT, when component pricing will shift to the New York Stock Exchange and NASDAQ markets from the Xetra trading system of the Deutsche Börse in Frankfurt.
Backtesting showed no major gaps between European and U.S. opening prices, said Sybille A. Reitz, spokeswoman. The move is a step toward eventual 24-hour real-time pricing of the DJIA, which "is dependent on getting pricing sources in Asia, she said, adding that could be a year or more away.