BTC / 10Y Correlation: An 18-Day Rupture, Priced at Zero

The BTC / 10Y Treasury correlation has inverted from +0.42 (Q1 2026) to −0.18 over 18 consecutive days. Statistically significant at 95%. Marc Steiner assigns P(structural signal vs noise) = 0.71. Institutional VaR models are underpricing tail risk right now. Brier-score-public.