The trading desks at Goldman Sachs ( GS) and Lehman Brothers ( LEH) are the champions of Wall Street, getting the most bang for their firms' bucks. A first-half analysis of earnings results for seven of Wall Street's biggest investment firms finds that the traders at Goldman Sachs and Lehman are most effective in generating big revenue for their employers. The worst, meanwhile, are the proprietary traders at Citigroup ( C), JPMorgan Chase ( JPM) and Merrill Lynch ( MER). The review, conducted by Brad Hintz, a Sanford Bernstein analyst, focused on risk-adjusted returns. To facilitate such a comparison, Hintz used a common securities industry metric that gauges a firm's exposure to trading losses on any given day, called "value at risk." He then divided a firm's total trading revenue by its average value at risk during the quarter. "We found that Lehman Brothers and Goldman Sachs were the best traders on Wall Street during the first half of '06,'' says Hintz in the report. "And each firm, over the past two-plus years, has exhibited the strongest correlation between risk taken and trading revenues generated amongst it peers.'' The analysis by Hintz comes at a time that revenue from proprietary trading -- trading for an investment house's own account -- continues to propel earnings on Wall Street to record levels. Over the past few years, trading revenue has become the big cash cow for most investment firms, far surpassing the fees Wall Street firms generate from advising on corporate deals or underwriting stock and bond offerings. In terms of trading, Goldman Sachs is far ahead of the pack when it comes to generating revenue. The firm's trading operation generated $13.6 billion in revenue during the first six months of 2006, nearly three times as much as most other investment firms. Morgan Stanley, which ranked second in terms of trading revenue, took in $7.8 billion during the first half of the year.