U.S. stock futures rose today, indicating the Standard & Poor's 500 Index may gain for a third straight day, as investors speculated central banks around the globe will step up efforts to revive the economy. General Electric Co. added 1.7 percent and Citigroup Inc. advanced in German trading. Adobe Systems Inc. lost 5.2 percent as the world's largest maker of graphics and Web-design software forecast sales that trailed analysts' estimates. Reports today may show factory orders declined in October, while more Americans last week filed for unemployment benefits. Futures on the S&P 500 expiring in December rose 2.3, or 0.3 percent, to 870.8 at 6:50 a.m. in New York. Dow Jones Industrial Average futures added 0.1 percent to 8,587, while Nasdaq-100 Index futures increased 0.3 percent to 1,159.25. The Federal Reserve announces its decision on borrowing costs Dec. 16. Futures traders now see a 52 percent chance the main rate will be lowered by 75 basis points to 0.25 percent, compared with a 36 percent probability a week ago. The S&P 500 is down 41 percent this year as credit losses and writedowns at financial firms approach $1 trillion and more economists forecast that the U.S. recession will be one of the most severe in the post-World War II era. U.S. stocks rallied yesterday as a jump in online spending and a record increase in mortgage applications lifted retailers and banks, overshadowing concern the worsening recession will reduce demand for commodities.