Developed by Welles Wilder, the Parabolic Sar refers to a price-and-time-based trading system. Wilder called this the "Parabolic Time/Price System." SAR stands for "stop and reverse," which is the actual Indicator used in the system. SAR trails price as the trend extends over time.The indicator is below prices when prices are rising and above prices when prices are falling. In this regard, the indicator stops and reverses when the price trend reverses and breaks above or below the indicator.