Hurst Exponent DFA

This script computes the Hurst exponent using Detrended Fluctuation Analysis (DFA) in TradingView. It works as follows:

- It takes a user-defined lookback window of closing prices and centers them by subtracting their mean.
- It builds a cumulative profile of these centered values.
- For each sample size input by the user, it divides the profile into non-overlapping segments, fits a local linear trend in each segment, and measures the root-mean-square fluctuation around that trend.
- It then performs a log–log regression of the average fluctuation versus segment size to estimate the Hurst exponent H.
- An optional exponential moving average smooths the Hurst series to reduce noise.
- A horizontal line at H = 0.5 helps distinguish trending regimes (H > 0.5) from mean-reverting regimes (H < 0.5).