** Shares of cybersecurity firm Fortinet FTNT.O fall 19.2% to $78.1in premarket trading

** Co forecast third-quarter revenue below Wall Street estimates on Wednesday, citing reduced business spending amid ongoing macroeconomic uncertainty and global trade tensions

** Piper Sandler downgrades stock to "neutral" from "overweight'; slashes PT to $90 from $135

** Brokerage Fortinet’s newer and more challenged narrative sets the stage for a multi-quarter ‘show-me’ period, particularly as year-over-year product comparisons become increasingly difficult

** J.P.Morgan also cuts PT to $87 from $105 and maintains a "neutral" stance, citing lower implied growth ex-refresh and reduced confidence in management’s ability to assess and manage expectations around the refresh impact

** Co expects Q3 revenue between $1.67 bln and $1.73 bln, with the midpoint slightly below analysts’ average estimate of $1.71 bln, according to data compiled by LSEG

** On average, FTNT is rated "hold"; the median PT is $100.8 - data compiled by LSEG

** As of Wednesday's close, the stock was up ~2.2% YTD

(Reporting by Akriti Shah in Bengaluru)

((akriti.shah@thomsonreuters.com))