IV rank & IV percentile
Where today's implied volatility sits against its own past year of readings.
Formula
IV rank = (IV − Lowest) ÷ (Highest − Lowest) IV percentile = Share of past readings below today's
How to read it
High means options are expensive relative to their own history. Rank moves with one outlier day; percentile does not. On the dossier both are withheld until 60 daily readings exist, and are taken over at most 252.
How to use it
High readings favor selling options, low readings buying them — other things equal.
In Kereon
Investing · company. Against Kereon's own daily archive of this company's at-the-money IV. Shown only once enough daily readings have been recorded — a percentile over a few weeks would read 100 the first time the market twitched.
Also called: iv rank, iv percentile.