Some of the big winners of 2012 are perhaps less surprising: Apple has risen 48 percent. Lions Gate Entertainment, the company behind the hit movies "The Hunger Games" and "Twilight," is up 67 percent.
As if the surge weren't enough, the markets impressed long-time stock investors with the way it climbed — slowly and steadily, without the wild swings of bravado and panic that characterized the market much of last year.
The gap between the daily high and low for the S&P has averaged about 0.9 percentage points. It was three times that early last fall, when the market was obsessed with debt problems in Europe and at home, among other fears.
Investor attention turns next to corporate earnings announcements, which begin when aluminum maker Alcoa, one of the 30 stocks that make up the Dow, reports April 10.
Companies in the S&P 500 are making more money than ever, an impressive feat in a tepid economic recovery.
Those who are bullish on stocks note that the S&P 500 trades at 12.9 times expected earnings this year, somewhat cheap compared with its 10-year average of 14.6.
The so-called forward earnings multiple is generally higher than the long-term average during bull markets. If it rose to 16 or 18 this year, stocks would be significantly higher than they are now, even if corporate earnings failed to grow at all.
Some investors say the bulls are fooling themselves if they think big profits this year are assured. Indeed, first-quarter profits for the S&P 500 are expected to fall 0.1 percent from a year earlier, according to a survey of analysts by FactSet, a provider of financial data.
That would be the first time in more than two years that earnings will not have grown. For the full year, analysts are expecting profits will rise a healthy 9 percent, but those predictions depend on a surge of 16 percent in the last three months.
"The idea that we're going to have a huge rebound at the end of the year is unrealistic," says Barry Knapp, head U.S. equity strategist at Barclays Capital.
Knapp says he's bullish on technology stocks but the rest of the market has "overshot the fundamentals." He says he's sticking with his target for the S&P this year: 1,330, which would be a drop of about 6 percent from Friday's close.
Other skeptics of the surge point to the role of central banks around the world in lifting markets by printing money, lending at near-zero rates and buying bonds and other securities.
The fear is that once that support is removed, stock prices could fall, and all the talk about profits could prove beside the point.
The same day the Nasdaq broke through 3,000 earlier this month, Michael Hartnett, chief global equity strategist at Bank of America, published a report with a curious chart showing how stocks reacted to programs by the Federal Reserve to buy bonds, or big announcements about lending rates.
In every case since the market hit a 12-year low in March 2009, prices jumped on the Fed moves, then fell when the programs ended. A question above the chart asked whether it was time to move more money into stocks.
Hartnett's answer was no. The bank expects the S&P to end the year at 1,400, almost exactly where it is now.
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