I priced every SPY put credit spread, 2018-2026 (18M trades). Theory -EV, reality +$1.06/spread.

A user's multi-year backtest of SPY put credit spreads showed a net positive return of +$1.06 per spread, defying theoretical negative expectancy. This suggests a systematic edge may exist in selling out-of-the-money put spreads on SPY, potentially due to the market's consistent overpricing of tail risk or the positive drift of the underlying. The data supports a systematic, repeatable strategy of selling SPY put credit spreads as a theta-positive, directional-neutral to bullish approach. The strategy is inherently short volatility and short tail risk. A sharp, rapid downturn in SPY would cause significant losses. The "theory -EV" warning implies the edge is not guaranteed and could reverse.