Economist David Rosenberg says the stock market has way overdone it on the upside.

The Standard & Poor’s 500 Index has soared 60 percent from its March low.

The S&P is at a level that should be reached in the third year of recovery from a recession, Rosenberg, chief economist at Gluskin Sheff & Associates Inc. in Toronto, told Bloomberg.

“The market is being really fueled here by technicals and momentum,” the former chief North American economist for Merrill Lynch said.

“It has overshot the fundamentals. I’m a little nervous, at least over the near-term.”

Earnings for companies in the S&P 500 Index have fallen for a record eight straight quarters and will probably plunge 22 percent in the current period before growing 62 percent in the final three months of 2009, according to the average estimate of analysts surveyed by Bloomberg.

Stock prices have surged to levels equal to almost 20 times reported earnings from continuing operations, the highest level in five years, according to weekly data compiled by Bloomberg.

“The fair multiple for earnings should be 12 or 13,” Rosenberg said. “We’ve blown right through that.”

Rosenberg isn’t the only bear.

“We think the market ... is due for a pullback or setback only because it's gone so far and economic growth cannot go so far," says Bill Gross, chief investment officer at bond giant Pimco, told CNBC.