Sustained low equity volatility and resilient market performance underpin the 91.5% market-implied probability against an NYSE market-wide circuit breaker before 2027. The VIX trading near 15–16 reflects contained daily S&P 500 moves well below the 7% Level 1 threshold, with the index near recent highs amid steady corporate earnings and no acute labor-market or policy shocks through late 2026. Circuit breakers have remained untriggered since the 2020 COVID episode, and even tariff-related volatility in 2025 fell short of activation. Elevated margin debt and potential geopolitical or inflation surprises represent realistic swing factors that could compress risk appetite and produce a sharp single-day decline capable of breaching thresholds.