piotroski
Piotroski F-Score Backtest: What 28 Years of US Data Actually Show
We ran the Piotroski F-Score on US value stocks from 1997 to 2024. Score 8-9 returned 6.1% vs 9.4% for SPY. Selection alpha is -1.6% per year. Avoidance alpha is +2.8%. The F-Score works as a floor (skip Score 0-2) but not as a ceiling in large-cap US.