30-day options IV rank and percentile

Source: recorded exchange public APIs, whole-chain hourly metrics. IV is annualized and displayed in percent; the comparison window covers the prior 30 calendar days of observed history. This is not an annual IV rank or a trade recommendation.

Range rank = 100 × (current IV − prior low) / (prior high − prior low). It is not clamped: below 0% means a new low, above 100% means a new high. A constant prior range has no defined range rank.

Midrank percentile = 100 × (reference observations below current + half the observations equal to current) / reference sample count. The current observation is excluded from its own reference window; duplicate hourly timestamps count once. A constant reference still has a defined percentile.

Coverage is observed unique reference hours / 720 possible hours in 30 days. Gaps are not filled, and a short observed window is not a full month of coverage. First/last timestamps describe the reference samples, separately from the current IV source timestamp. Both comparisons require at least 168 samples spanning 7 days and a current observation no older than 2 hours. Hidden venues never contribute to displayed combined history; a single public venue uses its own recorded series. Refresh: 120 seconds with history, 30 seconds when unavailable.