IV rank / IV percentile

How high today’s implied volatility is versus its own past year — a way to judge whether options are currently cheap or expensive.

IV rank and IV percentile both answer the same practical question: is the current implied volatility high or low for this particular underlying? Raw IV on its own tells you almost nothing, because a level that is cheap for a biotech stock might be expensive for a utility. IV rank looks at where today's IV sits between its lowest and highest points over the past year, usually 52 weeks. IV percentile instead measures the share of trading days in that window on which IV was lower than it is now.

Say a stock has an IV rank of 80. That means today's IV is near the top of its yearly range, so option premium is relatively rich. Many traders read a high reading as a signal to favour selling premium (credit spreads, covered calls, iron condors) and a low reading as a cue to lean toward buying options or debit structures. The two metrics can diverge: a single volatility spike inflates IV rank while IV percentile stays modest, so glancing at both gives a fuller picture.

The common mistake is treating a high number as a standalone trade signal. IV can stay elevated for a reason, such as an upcoming earnings report or a pending court ruling, and it can climb even higher. High IV rank tells you premium is expensive relative to the past year, not that the move is over. Pair it with the reason volatility is where it is before you act.

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Educational use only. Quotes are delayed ~15 minutes and nothing here is financial advice. Options trading involves substantial risk of loss.