We show that if a lead-lag relation exists between the option and spot markets, the implied volatility in option prices can be biased depending on the level of the true volatility; that is, the higher the true volatility, the more upward biased the implied volatility will be. We then test the...

We develop a theoretical model to study investors' trading behavior in the presence of large shareholders' influence on a firm's equity. We show that, for a good stock, large shareholders may invest a higher proportion of their wealth in the firm than smart small investors, although they predict...