Implied volatility & the expected move

The market's forecast of movement — and the single biggest edge in options.

Implied volatility (IV) is the annualized move the market is pricing into an option. It is not a prediction of direction, only of magnitude. High IV means expensive options; low IV means cheap ones. A one standard deviation expected move is roughly price times IV times the square root of days to expiry over 365.

The expected move

IV translates directly into an expected move: the ± range the stock is priced to stay within through a given expiry (about one standard deviation). The Arena shows this at the top of the options panel. Strikes beyond the expected move are long shots — priced cheaply for a reason.

IV crush

The classic earnings trap

Before a known event (earnings, FOMC), IV inflates because a big move is possible. The instant the event passes, IV collapses — and long options lose value on vega even if the stock moved your way. Buying pre-event and holding through is how traders lose on a correct call.

IV as an edge

The recurring edge in options is comparing the move the chain is pricing against the move you forecast. Buy volatility when it looks cheap relative to what you expect; sell it when it looks rich. Every advanced strategy is a version of this comparison.

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