In 1998, Goldman got more than two-thirds of its revenue from investment banking and asset management -- activities that help the economy by bringing capital and investors together. But by the first quarter of this year, revenue from trading and principal investment accounted for 80% of Goldman's total sales.

    Goldman's not alone in that shift. JPMorgan Chase (JPM, Fortune 500), Citigroup (C, Fortune 500), Morgan Stanley (MS, Fortune 500) and Bank of America (BAC, Fortune 500) also have been making more money from trading.

    So the Wall Street churn machine has done its damage. The question now is whether senators will stand up to the industry's financial muscle and pass reforms -- such as restrictions on bank holdings of derivatives -- that will serve to close the casino once and for all.

    "There's no doubt their behavior was unethical," Sen. John McCain, R-Ariz., said of Goldman. "The American people will render a judgment as well as the courts."