Does the model actually have an edge?

The honest stress test: walk-forward (no look-ahead), real costs, and a Monte Carlo placebo distribution. Numbers, not narrative.

1 · Walk-forward + costs — trust recomputed monthly from only-resolved calls; 0.3% round-trip friction; next-day fills

2 · Monte Carlo placebo — the same machine on N random-universe baskets. Where does the real strategy land?

3 · Risk-adjusted & significance