NEW YORK (Reuters) - Santa came early for Wall Street this year by giving the S&P 500 a 22 percent gain for 2009, and with just eight trading days left in the year, stock investors are not expecting to find much more under the tree.

The Grinch showed up early, too, with a heavy winter snowstorm on the East Coast forcing some stores and malls to close on "Super Saturday" — on the last holiday shopping weekend before Christmas.

Investors will be anxious to find out if consumers stepped up their online shopping to get all those stockings filled before Christmas morning, which falls on Friday this year.

With consumers in focus in the countdown to Christmas, this week's major US economic indicators will include the Reuters/University of Michigan consumer sentiment index, personal income and spending data, and the latest weekly jobless claims. On Thursday, the New York Stock Exchange trading floor will close early in observance of Christmas Eve. Financial markets will be closed on Friday for Christmas Day.

Investors will also pay attention this week to a final reading on third-quarter gross domestic product. But with the market already factoring in an economic recovery, the GDP data could evoke a muted response. Existing home sales and new home sales also will be worth noting, due to the central role the housing sector's collapse played in last year's financial crisis.

Tensions between Iraq and Iran over a disputed oilfield will also be on the radar and could hurt stocks if the situation escalates.

Markets historically enjoy a short, sweet "Santa Claus rally" in December's final days and early January.

But with the S&P 500 climbing 63 percent from March's 12-year closing low, investors question what catalyst could drive the market significantly higher.

"I thought there might be one more push higher, but it now looks like investors are willing to let the market consolidate its gains this year, and are happy to lock in the profits that they've established," said Michael Sheldon, chief market strategist at RDM Financial in Westport, Connecticut.

The Standard & Poor's 500 Index has drifted in a range between 1,085 and 1,119 since the start of November as market players became more concerned with preserving 2009's gains rather than taking risky bets. The S&P 500 is up 22.1 percent for the year.

This month, the US dollar's rebound has limited the stock market's gains as the inverse correlation between the greenback and equities deteriorated.

On the plus side, though, is the ritual of year-end window dressing, when fund managers sell underperformers and buy some gainers to spruce up portfolios, which could lift stocks that have done well this year.

Volatility may increase this week as fewer participants make it easier to push the market around. Indeed, the market has generally climbed on light volume this year, but most analysts expect stocks to grind sideways in the days ahead.

"You will probably see some modest window dressing going on, so in my opinion, you could see higher-quality stocks do a bit better," said Haag Sherman, co-founder and chief investment officer of Salient Partners, an investment firm in Houston. "But I don't think there's going to be any material movements between now and year-end."

Most importantly for the market's outlook, investors will assess the holiday shopping season after "Super Saturday" weekend. Retailers had hoped to see a surge of shoppers over the last weekend before Christmas. But that was before Mother Nature played her wild card with a huge East Coast snowstorm that made driving and even walking dangerous in many areas.

Even before the storm, experts doubted whether "Super Saturday" shopping would be enough to push holiday sales much above last year 's dismal tally.

Last year was the first time that holiday sales fell during this decade, according to the International Council of Shopping Centers, as shoppers fretted about the financial crisis and growing unemployment.

Spending has remained anemic this year. Consumers' reluctance to spend remains one of the biggest headwinds to the US economic recovery.

"Last year was a train wreck. It was the arctic winter of retail," said Lawrence Creatura, equity market strategist and portfolio manager at Federated Clover Capital Advisors in Rochester, New York. "Surpassing that is not a high hurdle."