Equity issuance across the world fell to $163 billion in the last half of 2011, down 53 percent from the first six months, according to data compiled by Bloomberg. Corporate bond issuance also skidded amid the European crisis and a weaker- than-expected U.S. economy.

Government efforts to prevent banks from trading with their own money also have an impact that may last, said Charles Bobrinskoy, the Chicago-based vice chairman and director of research at Ariel Investments, which has about $5 billion under management and owns shares of New York-based Goldman Sachs, JPMorgan, Citigroup Inc. and Morgan Stanley.

"It's a little of both -- it's a little bit of secular, a little bit of cyclical," he said.

Less Leverage

It doesn't help that lawmakers and regulators are seeking to limit financial maneuvers that boosted or masked leverage in the past, such as off-balance-sheet conduits, variable-interest entities and collateralized debt obligations, said Richard Bove, an analyst at Rochdale Securities LLC in Lutz, Florida.

"There's no more CLOs, CDOs, CDOs squared, CDOs cubed," Bove said, referring to asset-linked securities and financial instruments at the heart of 2008's U.S. financial crisis. "The leverage isn't there and the market isn't there. Banks can't grow at the same rate."

Citigroup reduced employees' 2011 compensation to account for a temporary decline in trading volumes and investor appetite, CEO Vikram Pandit, 55, told analysts Jan. 17. The bank also restructured reserves and sold certain assets where it sees a permanent shift in the market, he said.

"There's no magic answer," Pandit said. "It's very hard to parse out exactly what part of the activity we're seeing is the cause of the cyclical situation versus how much is secular."

BofA, Morgan Stanley

Citigroup, the third-biggest U.S. bank by assets, said Jan. 17 that net income dropped 11 percent as lower revenue from advising companies and trading securities led its investment bank to the first quarterly loss since 2008.

Goldman Sachs said fourth-quarter net income fell 58 percent, as revenue slid 30 percent. JPMorgan, the biggest U.S. bank, said last week that net income decreased 23 percent as investment bank earnings fell. San Francisco-based Wells Fargo & Co., which relies least on trading among the six banks, said a focus on loans helped soften a 4 percent drop in revenue. Its profit rose 20 percent.