Spectators at a Senate Banking and Currency subcommittee hearing can ordinarily be seated comfortably in a space the size of a legislative pigeonhole. But not last week, when sessions started by that subcommittee became the capital's top summer attraction, with S.R.O. crowds. At issue: Securities and Exchange Commission charges that the U.S.'s huge mutual-investment funds have overcharged their customers in the process of becoming a $40 billion industry that can reverse the direction of the stock market at a rumor's notice. Thus, the fortunes of millions of people could be at stake.
Offering broadly balanced, closely managed stock and bond...