In early February, the SEC confirmed that it was investigating whether the major brokerage houses were tipping off hedge funds to the trades the brokers handle for big clients like mutual funds. If that's happening, it would be a scandal.
The SEC is also likely to scour trading records to see if the brokers are using info about clients' moves to invest their own capital. If the SEC finds evidence that they are, the scandal would be enormous - and go to the heart of Wall Street's profit machine.
A big question mark hangs over Wall Street: How is it that the top firms consistently beat the odds, earning spectacular returns on their own investments? Last year the five biggest U.S. investment banks - Morgan Stanley (Charts), Goldman Sachs (Charts), Merrill Lynch (Charts), Lehman Brothers (Charts) and Bear Stearns (Charts) - generated $61 billion from proprietary trading, about half their total revenue and a 54 percent increase over 2005.
Those returns have raised eyebrows for years. "Even the greatest investors lose money at some point, but the Wall Street firms never seem to lose," marvels Tiger Williams, chief of Williams Trading, a firm that attributes its success to keeping its hedge fund clients' trades strictly confidential.
Just what the street needs -- another scandal. It does seem that each bull market brings a fair amount of scandal with it. What makes this interesting is the increased political blow-back against the Sarbannes-Oxley legislation enacted after the Enron scandal.
The firms names are some of the largest on the street. If this scandal blows up, it could get very ugly.