What IV Measures
Implied volatility is the expected future volatility of a stock, derived from current options prices. If IV is 50%, the market is pricing an annualized standard deviation of 50% in the underlying stock price.
Low IV ≈ options are cheap. High IV ≈ options are expensive.
Why Pros Trade IV, Not Price
Most professional options trading is about finding IV mispricings — options that are too cheap or too expensive relative to how much a stock will actually move. Direction can be hedged; getting the volatility call right is what produces alpha.
IV vs Realized Volatility (RV)
Realized volatility is what actually happened. IV is what the market expects to happen. The gap between them (IV – RV) is the variance risk premium. It is typically positive — options buyers pay for convenity, so IV tends to run above RV on average.
Earnings IV Crush
Before earnings, IV rises sharply because a binary event is coming. After earnings, IV collapses (the event is resolved). This is called IV crush.
A stock can beat earnings and go up, but if IV collapses more than the stock rises, a long call position can lose money. This is why naive earnings trades ("just buy calls before earnings") often fail.
IV Rank vs IV Percentile
- IV Rank: where current IV sits between the 52-week high and low (e.g., 80 means IV is near recent highs)
- IV Percentile: what percentage of days in the last 252 had lower IV than today
- Both normalize IV to be comparable across tickers and time periods
High IV Strategies
When IV is elevated, option selling strategies (covered calls, cash-secured puts, iron condors) have a volatility tailwind. You collect premium that tends to decay faster than the stock actually moves.
Low IV Strategies
When IV is low, option buying strategies (long calls, long puts, long straddles) have a volatility tailwind. Premiums are cheap relative to potential moves.
Term Structure
Options at different expirations can have different IVs. Normally longer-dated options have higher IV (the "contango" shape). During market stress, short-dated options can have higher IV than long-dated (backwardation) — a sign of acute near-term fear.
Skew
Puts at lower strikes typically trade at higher IV than calls at higher strikes (the "volatility smile" or skew). This reflects the market's demand for downside protection.
Using IV Data
Free data sources include Yahoo Finance, Barchart, and most brokerage platforms. Subscription tools (ORATS, livevol) provide finer-grained historical analytics.
Catalayer users create a Monitor around implied volatility OR IV crush OR options activity for their watchlist tickers.
Key Takeaways
- IV is the expected future volatility priced into options
- Pros trade IV mispricings, not direction
- Earnings cause IV to rise then crush post-announcement
- Use IV Rank / Percentile to normalize across tickers
- High IV favors selling strategies; low IV favors buying
Browse live options and earnings commentary at [/topic/earnings-season](/topic/earnings-season).