We present a two-factor volatility model to study the impact of news arrival and trading volume on stock returns variance. The model can explicitly account for the association between volatility and volume, as well as the persistence in equity variance. Unlike the standard "Mixture of...

The long-term performance of any portfolio can be decomposed as the sum of the weighted average long-term return of its assets plus the volatility return of the portfolio. Hence, maximizing the volatility return of portfolios of assets with similar characteristics, such as factor portfolios,...

In this paper, we formally show that the cross-sectional variance of stock returns is a consistent and asymptotically efficient estimator for aggregate idiosyncratic volatility. This measure has two key advantages: it is model-free and observable at any frequency. Previous approaches have used...