Does Parabolic SAR flip actually work on SPY? We tested it

This strategy made money, turning a 99% total return over 85 trades, and the ride was moderately steady with a Sharpe ratio above 1. The worst pain came from a single long drawdown of 13.54% that stretched from late 2021 to early 2023, which is a significant period of losses. The result is not just driven by a few lucky trades, since the win rate is a solid 60% and the average trade gained 0.84%. The entry timing is doing a lot of the heavy lifting here, because the real entries beat 82% of random entry runs, meaning the setup is good at picking when to get in. The edge also shows up consistently across different market periods, as the strategy was profitable in three out of four walk forward test periods, so the performance is not from one lucky stretch.