Not Excessive

"Even in the assumption that earnings growth is zero, valuations would not be excessively high," said Patrick Moonen, who helps manage $537 billion at ING Investment Management in The Hague, Netherlands. "We are below consensus in the estimated earnings growth, and still think the corporate momentum is very strong."

Disappointing reports since May on housing, employment and manufacturing have heightened concerns that $600 billion in Treasury purchases by the Fed have failed to bolster growth. The S&P 500 posted its biggest weekly decline since August in the period that ended June 3 after the U.S. jobless rate unexpectedly climbed to 9.1 percent and payrolls expanded at the slowest pace in eight months. A report from the Institute for Supply Management on June 1 showed that manufacturing expanded at the lowest rate in more than a year.

Greek Swaps Soar

The cost of insuring against defaults on Greek, Irish and Portuguese government debt surged to records last week on concern governments will fail to impose spending cuts needed for a European Union debt restructuring.

Credit-default swaps on Greece soared as much as 459 basis points to 2,237 on June 16, according to CMA prices, meaning it cost more than 2 million euros ($2.9 million) a year to insure 10 million euros worth of the nation's debt.

They traded at 1,932.75 basis points as of 4:30 p.m. in London on June 17 as Merkel backed down from her demands and said she'd work with the European Central Bank to avoid market disruptions.

Investors are concerned about slowing growth in the U.S. and Europe's sovereign debt crisis at the same time policy makers in China, the world's second-largest economy, are trying to cool expansion. The country's central bank has raised the reserve-requirement ratio for lenders 11 times and boosted interest rates four times since the start of 2010 to keep inflation in check.

Lehman, 1980s

Analysts are boosting profit forecasts even with the global economy showing signs of weakness. S&P 500 earnings may rise to $99.61 a share in 2011 from $84.58 last year and $61.52 in 2009, according to data compiled by Bloomberg. That's an increase from the forecast of $95.37 on Jan. 3 and $98.70 on April 29, the data show.