Piper Jaffray analyst Erinn Murphy is bullish on Fitbit (FIT) into the company's first-ever earnings report tomorrow, August 5. New product momentum and recently increased manufacturing capacity for Charge HR should drive the Q3 outlook above consensus estimates, Murphy tells investors in a pre-earnings research note. She also sees upside to her Q2 sales estimate of $325M, which is already above the $319M consensus. Murphy believes Fitbit's long-term growth prospects warrant a valuation multiple similar to other high-growth consumer facing brands such as Under Armour (UA), GoPro (GPRO) and LinkedIn (LNKD). The provider of health and fitness products closed yesterday up $1.43 to $49.03.