He was acquainted with several such cases among his brokerage clients.

First, he participated in nine I.P.O.'s when more than one would be unusual for an outsider who is not a brokerage client generating significant commissions.

Investment banks employ analysts to serve the bank's brokerage clients.

Bear Stearns, which has invested $1 million in Mr. O'Shaughnessy's company, plans to offer NetFolio's service to its wealthy brokerage clients, he said.

More than 50,000 Canadian brokerage clients, from 32 investment firms, had personal financial information on the device.

He said Goldman Sachs sold shares of new stocks only to executives who were brokerage clients of the firm and who requested them.

The firm suffered after the 1987 stock market crash because of its heavy reliance on brokerage clients.

The couple returned so enthusiastic about Fidel Castro's revolution that most of Mr. Bernstein's brokerage clients dropped him.

Invariably, some brokerage clients lose money.

Barron's raised the possibility that Madoff's returns were most likely due to front running his firm's brokerage clients.