Chief

//@version=4
study("", "", true)
gapbar_perc = input(75, minval=25, title="Gap Bar Size (%)")
gapbar = tr > (atr(14) * (gapbar_perc / 100))
lookback = input(5)
gap_true_above = low > high[2] and gapbar and hl2 >= highest(high, lookback)[1]
gap_true_below = high < low[2] and gapbar and hl2 <= lowest(low, lookback)[1]
barcolor(gap_true_above ? color.orange : na, title="Bull Gap Candle")
barcolor(gap_true_below ? color.black : na, title="Bear Gap Candle")
// Debug
plot(highest(high, lookback)[1], "", color.blue, 10, transp = 70)
plot(hl2, "", color.red)
plotchar(hl2 >= highest(high, lookback)[1], "hlg", "•", location.top)