Socking the Rock

The most important thing we earn is your trust." That Prudential Securities advertising slogan rang a bit hollow last week after the company agreed to pay the largest penalty ever levied against a brokerage for defrauding small investors. Prudential said it would repay at least $330 million to customers across the U.S. who lost money on the company's limited partnerships in the 1980s. The firm will pay another $41 million in fines. Even those hefty sums might be little more than a down payment: in settling with the Securities and Exchange Commission, Prudential said it will fully compensate all investors who...