SpyClosePressureOvershootFade tested a one-session fade of 2-sigma SPY moves that closed at the extreme of the day's range, backed by a strong pre-study (+0.26% per trade, t=3.6, replicated on QQQ, DIA and IWM). The base backtest reproduced the per-trade edge (388 trades, 0.286% avg, PF 1.69), but the modern-era result depended heavily on March 2020, and the daily-return series showed a suspected mark-to-market artifact. Optimization chose z_entry 1.0 and more than 1x sizing, which produced a 57% drawdown and a holdout Sharpe of 0.42 against 1.49 walk-forward OOS. The analyst abandoned it at iteration 5 as overfit, recommending a single re-test only after the artifact is fixed, using next-open fills, fixed 1x size, and only z_entry and close_extreme_frac free.