Stock Trades: A Better Deal For Investors Isn't Simple
Market Place column on 'best execution,' benign concept that means that brokers must try to do their best to make sure that when customers buy a stock they pay lowest price available and when they sell a stock they get highest price; says no one seems to agree on exactly what 'best execution' entails, or exactly how to achieve it; holds that is not surprising, considering that there are millions of dollars at stake for investors, brokerage firms and stock exchanges; holds Congressional lawmakers, who commissioned report by Securities and Exchange on arcane ways of stock trading, were put up to it by New York Stock Exchange, which contends that practices by rival exchanges--Cincinnati and Boston--favor brokerage firms over their customers; SEC says it is not necessarily so (L)