Using data that contain bid and ask quotes for both options and stocks, the analysis investigates the constant volatility assumption of the Black-Scholes model. The analysis adjusts for bid-ask spreads and finds evidence that is inconsistent with the constant volatility assumption. Instead, the results reveal a strong negative correlation between volatility and stock price, and they suggest that using a nonconstant volatility model such as the CEV model would be more appropriate to price long-term options. Finally, transaction costs associated with the dynamic hedge tend to increase with an option's maturity, but decrease as a percentage of the option's price.

We examine market behavior of the stock and option markets upon the arrival of noisy information in the form of CNBC’s Mad Money recommendations. If stock and option markets are not equally efficient, they should respond differently to noisy information, with the less efficient market more susceptible to noise. We find that the stock market is less efficient than the option market. The abnormal difference between option-implied and actual stock returns is negative and significant upon exposure to noisy information. This difference may yield an economically significant monthly trading profit of up to 5%. We conclude that the stock market is more susceptible to noisy information than the option market and is therefore less efficient.