IV Rank
Where current implied volatility sits within its own recent range, as a percentile — context an absolute IV number cannot give.
Also called: IV percentile · IVR · implied volatility rank
What it means
An IV of 18% means nothing in isolation: it may be the highest this instrument has printed in a year or near its floor. IV rank answers the question that matters by expressing the current reading as a percentile of its own recent history.
For an option buyer the asymmetry runs one way. High IV rank means premium is expensive and decay risk is elevated; low IV rank means premium is cheap and there is room for volatility expansion to help rather than hurt.
The window length is a real choice. Too short and the percentile is noise; too long and it spans volatility regimes that no longer apply.
How OptionLab Pro’s engine uses it
In the live engine
We rank the daily at-the-money IV snapshot against a 60-day rolling window and require at least 10 samples before showing a rank at all — below that the pill is hidden rather than showing a misleading percentile against a tiny sample. Thresholds are 70 for "Premiums Expensive" and 30 for "Premiums Cheap", tighter than the classic 80/20 because Indian index IV sits in a narrower band. The snapshot day is excluded from its own window, so the percentile answers "where am I versus the recent past" rather than including itself.
go/internal/iv/ (RankResult, MinSampleSize=10, DefaultWindowDays=60)The common mistake
Where traders get this wrong
Using IV rank as a buy or sell signal. It is context, not direction — and the colour convention for an option BUYER is inverted versus a stock pill: expensive premium is a caution, cheap premium is an opportunity. Reading "high IV = bullish" gets the sign exactly backwards.
Go deeper
There is a full lesson on this in the Academy, with an interactive widget and a Hindi translation.
Related terms
Educational and analytical content only. OptionLab Pro is not a SEBI-registered investment adviser or research analyst and does not give buy or sell recommendations. Derivatives trading carries a high risk of loss.