Stock volatility has been unusually low since the 1987 stock market crash. The large increase in stock prices since 1987 means that many days during 1996 and 1997 experienced near record changes in the Dow Jones Industrial Average, even though the volatility of stock returns has not been high by...

This paper uses monthly returns from 1802-2010, daily returns from 1885-2010, and intraday returns from 1982-2010 in the United States to show how stock volatility has changed over time. It also uses various measures of volatility implied by option prices to infer what the market was expecting...

The recent volatility of stock prices has caused many people to conclude that investors have become irrational in valuing at least some stocks. This paper investigates the behavior of the volatility of stocks on the Nasdaq, which tend to be smaller companies with more growth options, in relation...

We use predictions of aggregate stock return variances from daily data to estimate time varying monthly variances for size-ranked portfolios. We propose and estimate a single factor model of heteroskedasticity for portfolio returns. This model implies time-varying betas. Implications of...

This paper analyzes the behavior of stock return volatility using daily data from 1885 through 1987. The October 1987 stock market crash was unusual in many ways relative to prior history. In particular, stock volatility jumped dramatically during and after the crash, but it returned to lower....