Speculation that a major central bank will help to stimulate the global economy contributed to a roughly 2% gain in the market in mid-afternoon trading, pushing stocks back into positive territory for 2012. The Dow Jones U.S. Media Index is up 1.6% and the SNL Kagan Media and Entertainment Index is +1.9%. News Corp, up 3.5%, is enjoying the biggest jump among Big Media companies. It’s followed by Sony (+2.7%), Comcast (+2.1%), Viacom (+1.9%), Time Warner (+1.8%), CBS (+1.6%), and Disney (+1.1%). Elsewhere in media, LIN TV, Coinstar, and Entercom are up more than 6%, while Lionsgate and McClatchy are up at least 4%. Even Facebook is enjoying a rare bounce: It’s up 4.5%, but still off 29% from its IPO price last month. The day’s few decliners include Barnes & Noble (-1.4%), Cinedigm (-1.3%), and Sinclair (-1.0%).