The idea behind this indicator is to extrapolate a stationary time series and find the peeks of the extrapolated result. The highest and lowest of the extrapolated data represent really precise if the data and its extrapolation are barelly equal with an error lower than the average.
When the detrended price (in blue) crossover the lower level then the indicator detect a valey and the possibility of an up movement, if the higher is crossed down then the indicator detect a peek and the possibility a down movement.
When "Show extrapolated values" is checked the indicator will show the forecast of the detrended price with a forecast of length periods ahead.
Feel free to contact me for any questions regarding my indicators :)