Why Do Option Prices Not Always Reflect Changes in Underlying Asset Prices?
When trading options, you may notice that the underlying asset price has increased, yet a call option does not rise and may even decline. Similarly, the underlying asset price may decrease, while a put option does not rise and may also decline. This does not necessarily indicate delayed market data or a system error.
Option prices are influenced by multiple factors, not only the price movement of the underlying asset. These factors include implied volatility, time remaining until expiration, the relationship between the strike price and the underlying asset price, and market liquidity. As these factors change, an option’s price may move differently from the underlying asset, even when the underlying moves in a seemingly favorable direction.
Generally:
- When the underlying price increases, call options might not rise—if implied volatility decreases or expiration is near, the call option might decrease.
- When the underlying price decreases, put options might not rise—if implied volatility decreases or expiration is near, the put option might decrease.
| Observed Situation | Most Likely Cause |
| Underlying price rises, call option falls | Implied volatility drops significantly or option is near expiration |
| Underlying price falls, put option falls | Implied volatility drops significantly or time value decays rapidly |
| The underlying price remains mostly unchanged, but the option price keeps falling | Time value is decaying, especially when the option is close to expiration |
| The underlying price moves in a favorable direction, but the option price remains unchanged | The option is deep out-of-the-money and is not very sensitive to changes in the underlying price |
Example: Suppose you hold a call option with a strike price of $100. The underlying price rises from $95 to $98, which is favorable for the call option, but the option remains out-of-the-money. If implied volatility drops sharply from 50% to 30% at the same time, the option’s time value may decline significantly. As a result, the call option price may decrease even though the underlying price has risen. This is normal option pricing behavior and does not indicate delayed market data.
