Reforms have largely abolished the "private club" nature of Wall Street's brokerage community and made it far less important than it once was. Last December, for example, the Securities and Exchange Commission threw out the New York Stock Exchange's Rule 394, which had effectively limited competition by requiring that most stock transactions take place on the Big Board's floor. Now brokers face another threat to their exclusivity: competition from banks in the business of buying and selling stocks.
Soon New York's Chemical Bank, the nation's sixth largest (assets: $23.9 billion), is expected to announce a plan that will enable checking-account...