This is an experimental study designed to track the average magnitude of price movements.
First the range between high and low, and the range between open and close are calculated.
Then a positive and negative root mean square is taken of both ranges, and the results are smoothed with an exponential moving average.
And lastly, the median value between the ranges is calculated and smoothed with an ema to provide a signal line.
This study can be used to identify trending and detrending price activity.