IV rank / IV percentile
IVランク／IVパーセンタイル。現在のインプライド・ボラティリティが過去1年の水準に対してどれだけ高いかを示し、オプションが今割安か割高かを判断する指標。
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.
すべてのオプション用語
教育目的のみ。気配値は約15分遅延しており、本サイトの内容は投資助言ではありません。オプション取引には多大な損失リスクが伴います。