21. What Is Implied Volatility in Options?

Implied Volatility (IV) is a measure of the market’s expectations of how much the price of the underlying asset is likely to move in the future.

It is not based on past movements but is derived from the current price of the option.
IV reflects how volatile traders expect the asset to be until the option expires.

Implied volatility plays a central role in option pricing because it directly influences the premium paid or received when trading options.

What Does Implied Volatility Represent?

Example:

Important: IV does not indicate direction — only the expected size of movement.

How Is Implied Volatility Used in Option Pricing?

Options are priced using models like Black-Scholes, where volatility is a key input.

Impact:

Example

Two stocks trade at ₹1,000:

Even with the same strike and expiry, the option on Stock B will have a higher premium due to higher expected volatility.

Implied Volatility vs Historical Volatility
FeatureImplied VolatilityHistorical Volatility
Based onCurrent option pricePast asset price movement
IndicatesMarket’s expectation of future volatilityActual past movement
DirectionNo (only magnitude)No (only magnitude)
Affects PremiumYes — directlyNo

Traders often compare IV to historical volatility to find overpriced or underpriced options.

How IV Affects Option Premium
Implied VolatilityOption Buyer ImpactOption Seller Impact
High IVPays higher premiumCollects higher premium
Low IVPays lower premiumCollects lower premium
Volatility Crush

When IV falls sharply after events like earnings, option premiums drop even if the stock moves.
This is called volatility crush and often causes losses for option buyers.

Practical Use of Implied Volatility

Traders use IV to:

Key Takeaways
  1. Implied volatility (IV) is the market’s forecast of how much an asset may move until expiry.
  2. IV is derived from option premiums, not past data.
  3. Higher IV means higher premiums; lower IV means cheaper options.
  4. IV shows the size of expected movement, not the direction.
  5. Traders use IV to assess risk, opportunities, and strategy suitability in options trading.