Guessing game ahead of Facebook mystery event

Facebook shares wobbled Tuesday amid a guessing game ahead of a news conference set by the social network giant at its California headquarters. Shares opened higher but then slipped back in morning trade before moving up 0.02 percent at $30.95 at 1535 GMT, ahead of the company's 1800 GMT event at its Menlo Park campus. Facebook was mum about the details of the event, but analysts and media reports were abuzz with speculation about the possibility of a Facebook-backed smartphone, a new consumer mobile platform or details of the new engineering building designed by architect Frank Gehry. The latter possibility was sparked by the invitation from Facebook, which says: "Come and see what we're building." The company, which has built a user base of over one billion people worldwide, has nonetheless struggled since its stock offering in May. Shares in Facebook made a market debut at $38, but sank by more than 50 percent in the following months. The shares have clawed back some of those losses, and began the day down around 20 percent from the IPO level. Victor Anthony at Topeka Capital Markets sought to dash speculation about a Facebook smartphone but added that "what could be announced is deeper Facebook integration with carriers" to allow "further monetization of mobile." Anthony reiterated the brokerage's "buy" rating for Facebook, saying any of the speculated announcement at the event "would be a strong positive catalyst for the shares." Ross Sandler at Deutsche Bank said Facebook "could unveil a new search technology that helps users navigate the site much faster on PC and mobile," which could also be positive for the company.