U.S. stocks rose, following the biggest gain in a month for the Standard & Poor’s 500 Index, as the largest increase since 2003 in a gauge of consumer confidence bolstered optimism in the American economy.

Stocks extended gains as the Conference Board’s index increased to 56 from a revised 40.9 reading in October.

Europe’s effort to expand its bailout fund to 1 trillion euros ($1.3 trillion) is falling short, forcing renewed consideration of a role for the European Central Bank in insulating Spain and Italy from the debt crisis, two officials familiar with the discussions said.

Finance ministers will tonight hold an initial discussion on channeling ECB loans to cash-strapped euro nations through the International Monetary Fund, aiming to bring the central bank onto the front lines without violating its ban on direct lending to governments, said the people, who declined to be identified because the talks are at an early stage.

Dow 11,609.78 +86.77 +0.75%, Nasdaq 2,527.63 +0.29 +0.01%, S&P 500 1,201.46 +8.91 +0.75%

Yahoo! Inc. climbed 2.8 percent as two people with knowledge of the matter said private-equity firm Thomas H. Lee Partners is considering a bid for the Internet company.

Hewlett-Packard Co. (HPQ) gained 2.9 percent after RBC Capital Markets raised its recommendation for the computer maker’s shares.

Seagate Technology Plc jumped 3.6 percent to $16.56. The company forecast higher sales than analysts had estimated, saying it withstood flooding in Thailand better than much of the disk-drive industry.

Research In Motion Ltd. (RIM) rose 6.6 percent to $17.57. The BlackBerry maker was raised to “market perform” from “underperform” at Stanford C. Bernstein & Co., which said shareholder activism may lead to management change or a takeover.

Tiffany & Co. tumbled 8.5 percent to $67.38. The world’s second-largest luxury jewelry retailer cited “weaknesses” in sales in Europe and the eastern U.S. as the holiday season began.