** Shares of fintech co Block XYZ.N tumble 23% to $44.9 in biggest one-day fall in five years after FY profit forecast cut

** The payment firm lowers gross profit growth forecast for the year to 12% from 15% as it grapples with muted consumer spending fears

** Co expects Q2 gross profit growth of $2.45 bln, lower than Wall Street estimates of $2.54 bln

** At least 8 brokerage firms cut PT after results, including J.P. Morgan ("overweight", cuts PT to $60 from $90)

** JPM says co missing Q1 guidance with five weeks left in the quarter raises questions about quality of consumer base, competition and total addressable market penetration

** RBC cut PT to $63 from $86; says risk for co includes macroeconomic concerns, execution risks and competition in payments landscape with XYZ at risk from a slowdown in consumer retail sales

** XYZ reports a 60% drop in Q1 profit due to a $93.4 mln remeasurement loss on its bitcoin investments

** 36 out of 46 analysts rate stock as "buy" or higher, 9 "hold" and one "sell"; Median PT is $70

** Of last close, XYZ down 31.2% YTD vs other fintech firms PayPal PYPL.O falling 23.4%, Pagaya Technologies PGY.O slipping 22.3%

(Reporting by Twesha Dikshit)

((Twesha.Dikshit@thomsonreuters.com))