Wall Street rarely talks about its mistakes, but BTIG admitted in a note to clients Tuesday that it messed up with its call on Facebook . The firm raised its rating on the social network to buy from neutral because it believes the company's sales results will come in above Wall Street's expectations this year. "Not having a buy on Facebook has clearly been a mistake in 2017 and we are simply not going to allow that mistake to continue," analyst Rich Greenfield wrote in the report. "The secular trends toward mobile devices globally and the accelerating shift of ad dollars are simply too strong to ignore, particularly with the unexpected strength of Instagram Stories and visible signs that Facebook video strategy is evolving from its early missteps centered on live video." Facebook shares are up 22 percent this year through Monday compared with the S & P 500's return of 6 percent. The company reported better-than-expected fourth quarter earnings on Feb. 1. Greenfield initiated a Facebook price target of $175, representing 25 percent upside from Monday's close. He cited Facebook figures that Instagram Stories now has 150 million daily active users. The feature launched in August. "We initially dismissed Instagram Stories as copy-cat product (replicating one of the central components of its competitor Snapchat ). … However, over the past several months, it has become increasingly clear that Instagram Stories is an overwhelming success story for Facebook," he wrote. The analyst raised his 2017 Facebook revenue estimate to $38.7 billion from $35.9 billion versus the Wall Street consensus of $37.7 billion. "Thanks to Stories, Instagram not only has a real platform for video, but it has a way for brands to monetize with video ads. While very early days, we have been quite impressed with the quality of the brands choosing to utilize Instagram Stories' full screen, vertical video ad format," Greenfield wrote. — CNBC's Michael Bloom contributed to this story.
