The news rules have allowed ECNs to enter the market. On January 1999, 9
ECNs had been approved by Nasdaq. The combination of the handling and the
quote display rules allow each investor (and no longer only the most important
players) to have access to the best quotes.
The new SEC rules have deeply affected the ECN industry. Prior to the
changes, the presence of an alternative pricing system, by means of ECN, proprietary
trading systems, used by market makers and large institutions, permitted
dealers to quote one set of prices for retail customers on Nasdaq, while o¤ering
more favorable prices to other market-makers or institutions.