CORRECT ONE , B. Band calculate using ATR Percent, are smoother but still catch the divergences
study(shorttitle="BB+ATRP", title="Bollinger Bands with ATR(Percent)", overlay=true) //@version=2 //study("Average Percentage True Range") len=input(14,"ATRP") lh = high - low pc = close[1] hc = abs( high - pc ) lc = abs( low - pc ) MM = max( max( lh, hc ), lc ) atrs = iff( MM == hc, hc / ( pc + ( hc / 2 ) ), iff( MM == lc, lc / ( low + ( lc / 2 ) ), iff( MM == lh, lh / ( low + ( lh / 2 ) ), 0 ) ) ) APTR = 100*atrs*(2/(len+1))+nz(APTR[1])*(1-(2/(len+1))) //plot( APTR,title= "APTR" ,color=red ) length = input(20,"BB", minval=1) src = input(close, title="Source") mult = input(2,step=0.1, minval=0.001, maxval=50) basis = sma(src, length) dev = mult * APTR upper = basis + basis*dev/100 lower = basis - basis*dev/100 plot(basis, color=red) p1 = plot(upper, color=blue) p2 = plot(lower, color=blue) fill(p1, p2)