Information transmission in electronic versus open-outcry trading systems: An analysis of US equity index futures markets

In this article the intraday price discovery process between regular index futures (floor trading) and E-mini index futures (electronic trading) in the S&P 500 and Nasdaq 100 index futures markets is examined, using intraday data from the introduction of the E-mini index futures to 2001. Using both information shares (Hasbrouck, J., 1995) and common long-memory factor weights (Gonzalo, J., & Granger, C. N& J., 1995) techniques, we find that both E-mini index futures and regular index futures contribute to the price discovery process. However, since September 1998, the contribution made by E-mini index futures has been greater than that provided by regular index futures. Based on regression analysis, we have also found direct empirical evidence to support the hypothesis that the joint effects of operational efficiency and relative liquidity determine the greater contribution made towards price discovery by electronic trading relative to open-outcry trading over time. (c) 2005 Wiley Periodicals, Inc.