We investigate whether stock betas vary with the release of firm-specific news. Using daily firm-level betas estimated from intraday prices, we find that betas increase on earnings announcement days and revert to their average levels two to five days later. The increase in betas is greater for...

Using a variety of different definitions of "neutrality," this study presents significant evidence against the neutrality to market risk of hedge funds in a range of style categories. I generalize standard definitions of "market neutrality," and propose five different neutrality concepts. I...

We investigate whether stock betas vary with the release of firm-specific news. Using daily firm-level betas estimated from intraday prices, we find that betas increase on earnings announcement days and revert to their average levels two to five days later. The increase in betas is greater for...

25 years of volatility research has left the macroeconomic environment playing a minor role. This paper proposes modeling equity volatilities as a combination of macroeconomic effects and time series dynamics. High frequency return volatility is specified to be the product of a slow moving...

We propose a new method for pricing options based on GARCH models with filtered historical innovations. In an incomplete market framework, we allow for different distributions of historical and pricing return dynamics, which enhances the model's flexibility to fit market option prices. An...

Twenty-five years of volatility research has left the macroeconomic environment playing a minor role. This paper proposes modeling equity volatilities as a combination of macro- economic effects and time series dynamics. High-frequency return volatility is specified to be the product of a...