Hi all, I have a question about the varitaion in Implied vol with relative values of Spot price S and strike price X. I understand that implied vol is used to measure the volatility on the basis of existing options cost. Also the option cost increases as the volaitility of the stock increases according to Black-Scholes. So the converse must also be true and that implied vol increases as the option cost increases. Now considering a Put option. The price of the put option (P) increases as X is increased with respect to S. I expect the implied vol to increase as P increases due to logic presented in the previous paragraph. However, in the data presented in a text book (Derivatives market by Robert McDonald) shows that implied vol decreases as P increases. Am I missing out something here ?