The backtest equity curve for graph emergence. Each run on the walk-forward ledger plots its in-sample (train/validation) lift-over-null against its out-of-sample (test/holdout) lift. The shaded band is the gap between them — the one quant question that governs everything: is structure reproducing out-of-sample, or am I overfitting? A positive, growing in–out gap is the overfit warning. The dashed line at lift = 1 is chance. Filled markers survive all stochastic nulls; hollow markers are underpowered.