Plots the values between current close and close (specified number of periods) ago. User chooses the period defaulted to 1 and the period of a of the values in the series. Made this specifically to measure the drift of the VIX exchange traded funds VXX , UVXY and SVXY . The fact that they must drift can be strategic in trading.
In the chart example it shows that VXX drifts down usually between -$10 and -$20 over a 60 day period (eyeball) and that for a few days in February of 2017 it had drifted down -$75. To find a positive change (briefly) you can see you have to go back to November of 2016. If you use Heiken Ashi candles or ohlc bars or change between regular candles and these there is a set of variables in this code that lets you do that without changing your indicator results. Anyhow use it or any of the code if it helps you, good luck with your trading and keep smiling! (any feedback appreciated also :-) )