NEW YORK — Wall Street appeared ready today to extend its big rally into a second day.

Stock index futures pointed sharply higher after markets around the world followed the lead of U.S. investors who bought stocks furiously Tuesday on news that Citigroup Inc. was operating at a profit.

However, analysts were still very cautious, noting that it's common for the stock market to blip up after a prolonged period of selling. They also noted that investors are well aware of the many problems facing the economy.

"Right now we're not getting encouraging fundamental data," said Alan Gayle, senior investment strategist at RidgeWorth Investments. "I think it's too soon to call a bottom in this market despite yesterday's strong performance."

There is little economic and corporate news expected today. Investors are likely to keep a close watch on financial stocks, especially as they await details on the government's plan for dealing with banks' toxic assets. Treasury Secretary Timothy Geithner said Tuesday that the Obama administration will unveil the plan within the next couple of weeks.

During a television interview Tuesday night, Geithner said the plan the administration has put together will provide financing to private investors who are willing to buy banks' bad assets. He predicted the plan will succeed but will take time to work.

Ahead of the market's open today, Dow Jones industrial average futures rose 43, or 0.6 percent, to 6,930. Standard & Poor's 500 index futures added 7, or 1 percent, to 723, while Nasdaq 100 index futures rose 15.75, or 1.4 percent, to 1,121.75.

The big question today is whether the market can maintain its momentum throughout the day. If the Dow is able to extend its gains, it would mark the index's first back-to-back advance since early February.