It will be buy when high above previos DAPD high and sell if low below previos DAPD low This indicator is similar to Bollinger Bands. It based on DAPD - Daily Average Price Delta. DAPD is based upon a summation for each of the highs (hod) for the 21 days prior to today minus the summation for each of the lows (lod) for the last 21 days prior to today. The result of this calculation would then be divided by 21.