Factors Affecting Option Value
Learning Outcome Statement:
identify the factors that determine the value of an option and describe how each factor affects the value of an option
Summary:
The value of an option is influenced by several factors including the value of the underlying asset, the exercise price, time to expiration, the risk-free interest rate, the volatility of the underlying, and any income or costs related to owning the underlying asset. Each of these factors affects the option's value in specific ways, either increasing or decreasing it based on the type of option (call or put) and the nature of the change in the factor.
Key Concepts:
Value of the Underlying
Changes in the value of the underlying asset affect the value of options. For call options, an increase in the underlying's value increases the option's value, while for put options, it decreases.
Exercise Price
The exercise price sets a threshold that determines the profitability of exercising an option. Lower exercise prices increase the value of call options and decrease the value of put options.
Time to Expiration
Longer time to expiration generally increases the value of options by providing more time for the underlying asset's price to move favorably. However, for deep-in-the-money put options, a longer time can reduce the option's value due to the lower present value of the exercise payoff.
Risk-Free Interest Rate
Higher risk-free rates decrease the present value of the exercise price, thus increasing the value of call options and decreasing the value of put options.
Volatility of the Underlying
Higher volatility increases the potential for the underlying's price to reach favorable levels, thus increasing the value of both call and put options.
Income or Cost Related to Owning Underlying Asset
Income benefits like dividends decrease the value of call options and increase the value of put options. Costs like storage or insurance increase the value of call options and decrease the value of put options.
Formulas:
Call Option Exercise Value
Calculates the exercise value of a call option, which is the maximum of zero or the difference between the spot price and the present value of the exercise price.
Variables:
- :
- Spot price of the underlying at time t
- :
- Present value of the exercise price
Put Option Exercise Value
Calculates the exercise value of a put option, which is the maximum of zero or the difference between the present value of the exercise price and the spot price.
Variables:
- :
- Spot price of the underlying at time t
- :
- Present value of the exercise price