** Ride-hailing firm Lyft's LYFT.O shares fall 3.6% to $19.15 premarket
** Wedbush downgrades stock to "underperform" from "neutral"
** "Lyft is most at risk to the impact of (autonomous vehicle) disruption given the company’s exposure to the U.S. ridesharing market and undiversified offering mix" - brokerage
** Avg rating of 49 analysts is "hold;" their median PT is $24.03 - data compiled by LSEG
** Up to last close, stock has risen ~54% this year
(Reporting by Anhata Rooprai in Bengaluru)
((Anhata.Rooprai@thomsonreuters.com))