find out extraordinary volume change
study(title="absolute & relative volume change", shorttitle="ARVC") //absolute volume change x = input(5, minval=1) y = sum(volume, x+1)-volume z =x * volume / y Aupper = input(2.00, minval=0.01) Alower = input(0.5, minval=0.01) //relative volume change t = change (volume) length = input(20, minval=1), mult = input(2.0, minval=0.001, maxval=50) basis = sma(t, length) dev = mult * stdev(t, length) Rupper = basis + dev Rlower = basis - dev barcolor((z>Aupper and (t>Rupper or t<Rlower))? fuchsia : na) barcolor((z<Alower and (t>Rlower or t<Rlower))? yellow : na)