News Summary: Facebook stock surges

STOCK SURGE: Facebook's stock gained the most in a single day since its May IPO, closing up 19 percent, or $3.73, at $23.23 Wednesday.

MOBILE RELIEF: Several analysts upgraded the social network after its third-quarter results were posted Tuesday, which detailed for the first time how much money it makes from mobile ads. Mobile had been a concern since before the company's initial public stock offering.

STILL DOWN: Despite Wednesday's gain, Facebook remains 39 percent off its IPO price of $38.