How does the option price calculator work?
It uses the Black-Scholes model: from the underlying price, the strike, the time to expiry and the implied volatility it works out the fair premium of the call and the put, and their Greeks.
What are the Greeks?
Delta: how much the premium moves for a 1-point move in the underlying. Gamma: how much delta changes for a 1-point move. Theta: how much premium the option loses in a day if nothing else changes. Vega: how much the premium changes for a 1-point change in IV.
Why is there no interest rate?
Index options are priced off the futures, which already include the interest rate, so we use none, the same as our option chain. The figures then match the IV and Greeks shown there.
How do I find the implied volatility of an option?
Enter the option's premium in the second box: the calculator finds the IV at which the model gives that premium. Use live figures to start from today's price, ATM IV and expiry. This is information only, not investment advice.