Shares of Pandora Media Inc. P, +5.51% are up 5.9% in premarket trading Thursday after Raymond James analyst Justin Patterson upgraded the stock two notches, to strong buy from market perform. Patterson's upgrade comes on the heels of Pandora's announcement that it would be buying AdsWizz, an ad-tech platform that Patterson's "back-of-the-envelope math" says could be worth about $4 a share. Patterson sees AdsWizz giving Pandora exposure to the $28 billion worldwide market for audio advertising and expanding the company's reach. "A platform shift is underway with smart speakers," Patterson wrote. "This creates the need for audio-based ad formats, which Pandora is uniquely positioned for." Patterson assigned a $8 price target to Pandora shares, which are down 58% over the past 12 months. The S&P 500 SPX, -1.38% is up 15% in that time.