Keep an eye on Wal-Mart ( WMT). The retail giant on Monday reported same-store sales at the low end of its guidance for the first week of December. The disappointing sales figures follow similar results for the month of November. Last week, Wal-Mart reported that its same-store sales last month grew by 2.6%, toward the bottom of its projected range of 2% to 4%. The weak holiday sales so far call into question the company's ability to meet Wall Street's expectations for its fourth-quarter results, said Bill Dreher, an analyst with W.R. Hambrecht, in a research note issued Monday. Wall Street analysts expect Wal-Mart to post profits of 55 cents per share in its fourth quarter, which ends Jan. 31. "While the company still expects to make its sales plan for the month, we believe that the shorter holiday selling season, aggressive promotional environment and more conservative consumer spending may limit upside and weigh on the shares," Dreher said in his report. (W.R. Hambrecht does not have an investment banking relationship with Wal-Mart.) The questions about Wal-Mart's revenue and growth come as the company valuation is also under scrutiny. Wal-Mart is trading at nearly 30 times its projected earnings for its current fiscal year, well above its historic average, Dreher noted. The company's shares closed down $1.19, or more than 2%, to $51.85 on Monday. Wal-Mart's stock is down about 10% year to date. Wal-Mart had projected that its December same-store sales would grow between 3% and 5% from a year ago. Same-store sales figures compare sales made by stores open for at least a year. Although the company's sales came in at the low end of its range last week, Wal-Mart reaffirmed its guidance on same-store sales for the month.