Celcuity gains; J.P. Morgan initiates coverage with 'overweight'

** U.S. biotechnology firm Celcuity CELC.O shares rise 2.3% to $84.50 in premarket trading

** J.P. Morgan initiates coverage with "overweight" rating; PT $157 ** Says rating "driven by the long-term potential of Revtorpyk in breast cancer"

** Adds that "we see several long-term upside levers in the model, including Revtorpyk penetration/ramp in the 2L (second-line treatment) setting, potential in the front-line setting, and potential indication expansion."

** Co posted narrower-than-expected loss in Q2

** Up to last day's close, shares down 17.2% YTD