Welles Wilder's four indicators
1978, Welles Wilder published a book named New Concepts in Technical Trading Systems. In this book, he introduced four indicators to readers, including Average True Range, Relative Strength Index(RSI), Directional Movement Concept(ADX) and Parabolic SAR. Despite being developed many years ago, I am still surprised by their rigorous logics and practicality recent days. 1. Average True Range (ATR) 1.1 Calculation parameter: period = 14 TR = max(current High - current Low, current High - previous Close, current Low - previous Close) Current ATR = ([(Prior ATR)*13] + current ATR)/14 1.