A refined approach to estimating the implied volatility

In this paper we used a refined approach to estimating the implied volatility from options price in the classic framework developed by Black and Scholes (1973) and Merton (1973). Our study extend the formula previously developed by Corrado and Miller (1996) which works well for the Index options with the present value of strike price being close to the index price. Our refined approach provides more accurate implied volatility estimation over a wider range of moneyness.