OPTIONS FIELD GUIDE · 02
Implied Volatility
Implied volatility translates option prices into a common annualized scale. It describes the magnitude of movement embedded in option prices. Direction requires a separate view.
IV is backed out of current option prices using a pricing model.
A higher IV implies a wider expected distribution. Directional bias requires other signals.
Strike, tenor, events, and the symbol’s own history all matter.
Historical volatility and implied volatility answer different questions
Calculated from observed underlying returns over an explicit historical window, such as 20 market sessions.
Derived from an option quote for a specific strike and expiration, then expressed as an annualized volatility.
Comparing IV with realized volatility can reveal a volatility premium. That premium can reflect event, jump, liquidity, and risk-aversion risk.
One symbol has many implied volatilities
Current IV’s position between its trailing low and high.
Share of prior observations below today’s IV.
How IV varies across strike and expiration.
(current IV − trailing low) ÷ (trailing high − trailing low)Vega labels every lookback explicitly. A 252-session IV rank and a 30-session IV rank describe different historical contexts; neither should be read without its window.
Events can dominate the front of the curve
Scheduled earnings often lift near-term option prices because the contract spans a discrete uncertainty event. After the announcement, that event variance disappears and IV can fall sharply—often called an IV crush—even if the stock moved in the expected direction.
Estimates and removes positive discrete event variance from the 14/30/60-day ATM total-variance curve. This derived context metric is calculated from the observed curve.
Expected move is a range estimate
A quick one-standard-deviation annualized-volatility approximation is spot × IV × √(days ÷ 365). An ATM straddle offers a quote-derived alternative. Neither predicts direction or guarantees containment.
Compare volatility in context.
Rank IV, IV percentile, skew, term slope, and earnings-adjusted IV across the current options universe.