This is a "standard" Relative Strength Index (RSI) indicator with an ultralinear smoothing instead of a common one.
The indicator uses the CJurX class of the SmoothAlgorithms.mqh library. The use of this class is described in the article "Averaging Price Series for Intermediate Calculations Without Using Additional Buffers".
Generated indicator was smoothed using the CJJMA class from the same file. All standard elements of the technical analysis can be applied to this indicator.
Translated from Russian by MetaQuotes Software Corp.
Original code: https://www.mql5.com/ru/code/426
Reference Fast Trend Line (RFTL).T3Taotra
The fan based on the five T3 moving averages for trend indication.