I want to calculate the implied volatility from the option data that I took from Bloomberg (call Option written on S&P500 index with the maturity of 19-Dec-2009 and strike of 1300), but volatility comes out to be zero. Do you have any ideas how I can calculate the volatility or correct the data?
- As the risk free rate I normally use the 3 month TBill rate.
- As the Last price of the option I use the average of the Bid and Ask Prices (Bloomberg last price is not available for the most of the data points).
Thank you.
Date Bid Price Underlying Interest Rate Time to Maturity Ask Price Last Price
22/12/2006 272.5 1411.73999 0.055555 2.989041096 276.5 274.5
26/12/2006 278.5 1417.869995 0.055463 2.978082192 282.5 280.5
27/12/2006 285.8 1427.709961 0.055666 2.975342466 289.8 287.8
28/12/2006 285.1 1425.089966 0.05538 2.97260274 289.1 287.1