This indicator is built to mesure the performance of a stock vs the index of choice. it is best use for the intraday session because it doesn't take gap into account when doing the calculation. This is how i made my math (using AAPL compared to SPY for simplicity)
(change AAPL / ATR AAPL) - (change SPY / ATR SPY) * beta factor * volume factor
change is calculated...
