Читать книгу Candlestick Charting For Dummies - Russell Rhoads - Страница 28

The definition of a trading “day” used to be very simple. Trading was done on a central exchange with specific opening and closing times. Trading on stocks listed on the New York Stock Exchange (NYSE) or Nasdaq, for example, began at 9:30 a.m. and ceased at 4 p.m. These days trading in these stocks commences on some electronic communication networks (ECNs) hours before the formal listed exchanges open hours. (An ECN is a network of brokerage firms and traders, which allows for trading directly between the brokerage firms and traders.) A “day,” therefore, is much different from what it was in the past. Throw in futures exchanges and currency markets that trade almost 24 hours a day, and this issue becomes even more confusing. With all that trading going on outside exchange hours, what constitutes an actual day for data purposes?

Currently, in the case of stocks, the official open and close are based on the primary exchange they trade on, but in this world of expanding electronic trading, the actual open and close are becoming more blurred. With respect to futures markets that trade almost 24 hours a day, it’s almost impossible to pin down a day. For daily testing, I use data between 7 a.m. Eastern Time and the close at 3 p.m. to constitute a day.