Options: Greeks Flashcards
What factors does an options’s value dpend on and what are the letters representing them?
- Price of the underlying: S/F
- Strike price: K
- Volatility: σ
- Time to maturity: t
- Interest rate: r
What factors affect the Intrinsic Value of an option?
- Price of the underlying
- Strike price
- Time to maturity (indirectly)
- interest rate (indirectly)
What factors affect the Time Value of an option?
- Price of the underlying
- Strike price
- Volatility
- Time to maturity
- Interest rate (indirectly)
What are greeks?
Options’ sensitivity to each risk factor can be measured through partial derivatives of the option’s value respective to each factor. The sensitivities derived in this way are referred to as greeks.
What risk factor does greek correspond to?
- Price of underlying: Delta and Gamma
- Volatility: Vega
- Time to maturity: Theta
- Interest rates: Rho
What is the formula for Delta?
Dleta is the hedge ratio for an option.
Delta = Change in the value of the option/Change in the value of the underlying asset
What is the formula for Gamma?
How sensitive our hedge is to changees in the stock price.
Gamma = Change in the value of the option’s delta/Change in the value of the underlying asset
(Second derivative to value of the option)
What is the formula for theta?
How does option value change with time decay
Theta = Change in the value of the option/Decrease in the time to expiration
What is the formula for Vega?
How does option value respond to change in asset’s volatility?
Vega = Change in the value of the option/Change in the volatility
What is the formula for Rho (written as RhoD)?
Rho represents the sensitivity of the option’s value to the change in the interest rate
RhoD = Change in the value of the option/Change in the value of the interest rate
What are the deltas for a call?
- Out of the money call Delta approaches 0
- At the money call Delta close to 0.5
- In the money call Delta approaches 1 the more in the money (above K) it is
What are the deltas for a put?
- In the money put Delta approaches -1 (the more in the money, the more lower than K, the closer to -1)
- At the money put delta close to -0.5
- Out of the money put delta approaches 0 from the negative side
How do we interpret delta?
- Delta quantifies the impact of a change in the underlying asset price on the value
Delta = ΔV/ΔPunderlying => ΔV = Delta * ΔPunderlying - Delta > 0 (+) -> bullish position
- Delta < 0 (-) -> bearish position
- Delta = 0 -> neutral position
How does one calculate the Delta for a portfolio?
We just take the weighted sum of Delta, weighting by the units of each option
Why is Gamma needed?
Delta is not constant but varies with the price of the underlying, as such we need the derivative of delta to see its sensitivity to changes in the price of the underlying. Gamma is the second derivative of the value of the option V with respect to Price of the underlying.