Implied volatility explained: what IV means for traders

By Ken Chigbo, Founder, KenMacro. Published 2026-05-13.

What is implied volatility?

Implied volatility, often shortened to IV, is the volatility figure that, when input into an option pricing model such as Black-Scholes, returns the option’s current market price. It is not a historical measurement; it is forward-looking, reverse-engineered from what buyers and sellers are actually paying for optionality today. IV is quoted as an annualised standard deviation of returns, typically as a percentage. Each strike and expiry on an option chain carries its own IV, and the pattern across strikes forms the volatility smile or skew. Across expiries, the pattern forms the volatility term structure. Both shapes carry information about positioning, hedging demand, and event risk.

How traders use implied volatility

Retail traders use implied volatility to judge whether options are expensive or cheap relative to recent realised moves, comparing IV to historical volatility or to the asset’s own IV rank and percentile over the past year. Institutional desks decompose the IV surface to isolate event premium around scheduled risk such as central bank meetings, CPI prints, and earnings, then trade the difference between implied and expected realised volatility. FX traders watch one-month and three-month IV on majors like EUR/USD and USD/JPY for shifts in risk sentiment, since rising IV typically coincides with hedging flows and stress. Equity index traders use the VIX, which aggregates S&P 500 option IV, as a broad gauge of expected market turbulence.

Common misconceptions about implied volatility

The first misconception is that high IV means the market expects the price to fall. IV is directionless; it measures the size of expected moves, not their sign. Puts and calls at the same strike share the same IV under put-call parity. The second is that IV predicts realised volatility accurately. On average, implied tends to trade above subsequent realised, the so-called variance risk premium, which is why systematic option selling has historically earned a return. The third is treating a single IV number as definitive. The full volatility surface, across strikes and expiries, carries far more information than any one quote.

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Frequently asked

What is the difference between implied and historical volatility?

Historical volatility, sometimes called realised volatility, measures how much the underlying has actually moved over a past window, usually the standard deviation of daily log returns annualised. Implied volatility is forward-looking and extracted from current option prices. Historical tells you what happened; implied tells you what the market is pricing for the future. The gap between the two, often called the variance risk premium, is itself a tradeable signal.

Why does implied volatility rise before earnings or central bank meetings?

Scheduled events introduce known dates with unknown outcomes, increasing the range of plausible price paths. Option buyers bid up premiums to hedge or speculate on the outcome, and dealers raise IV to compensate for the risk of large gaps. After the event passes and uncertainty resolves, IV typically collapses, a pattern known as volatility crush. This is why buying options into earnings often loses money even when the directional view is correct.

What does IV rank mean?

IV rank places the current implied volatility within its range over a lookback window, usually fifty-two weeks. An IV rank of eighty means current IV is higher than eighty per cent of readings in the past year. IV percentile is a related measure showing the share of days where IV was below the current level. Both are used to judge whether option premium is rich or cheap in a context-specific way, rather than relying on the raw IV number alone.

Can implied volatility be used to forecast price direction?

Not directly. IV is a magnitude measure, not a directional one. However, the shape of the IV skew can carry directional information. In equity indices, out-of-the-money puts typically trade at higher IV than out-of-the-money calls, reflecting persistent hedging demand for downside. Sharp shifts in skew, or in risk reversals in FX markets, can indicate changing positioning and demand for tail protection, which traders sometimes interpret as a sentiment signal.

Educational analysis only. Past performance does not guarantee future results. Manage risk against your own portfolio.