More importantly, brokers would provide investment ad- vice. Although todays investor has access to more and more information, this does not mean that he has more understanding of the forces that rule the market or the principles of constructing the best portfolio. As the spread between the best bid and offer price has collapsed to 1/16th of a point in many cases-decimaliza- tion of prices promises to reduce the spread even fur- ther-some traditional concerns of regulators are less pressing than they once were. Whether to allow dealers to step in front of customers to buy or sell, or allow broker- ages to cross their orders internally at the best price, re- gardless of other orders at the price on the book, have traditionally been burning regulatory issues. But with spreads so small and getting smaller, these issues are of virtually no consequence to the average investor as long as the integrity of the order flow information is maintained. None of this means that the SEC can disappear once it establishes the central order-flow system. A regulatory authority is needed to monitor the functioning of the new systems and ensure that participants live up to their promises. But Mr. Levitts speech was a breath of fresh air in an increasingly anxious marketplace. The rise of technology threatens many established power centers and has prompted some to call for more controls and a go-slow approach. By making clear that the commis- sions role is to encourage competition to best serve in- vestors, not to impose or dictate the ultimate structure of the markets, the chairman has poised the SEC to take stock trading into the new millennium.     Source: Jeremy J. Siegel, "The SEC Prepares for a New World of Stock Trading," The Wall Street Journal, September 27, 1999. Reprinted by permission of Dow Jones & Company, Inc. via Copyright Clearance Center, Inc. 1999 Dow Jones & Company, Inc. All Rights Reserved Worldwide.       do not actually execute orders, instead sending an order either to a market maker or to a stock exchange for some listed stocks. Such practices raise serious ethical questions, because the brokers primary obligation is to obtain the best deal for the client. Payment for order flow might be justified if the re- bate were passed along to the client either directly or through lower commissions, but it is not clear that such rebates are passed through. Online trading and electronic communications networks have already changed the land- scape of the financial markets, and this trend can only be expected to continue. The ac- companying box considers some of the implications of these new technologies for the future structure of financial markets. I. Introduction 3. How Securities Are Traded The McGraw−Hill Companies, 2001