We develop a conditional capital asset pricing model in continuous-time that allows for stochastic beta exposure. When beta co-moves with market variance and the stochastic discount factor (SDF), beta risk is priced, and the expected return on a stock deviates from the security market line. The...

Aggregate implied volatility spread (IVS), defined as the cross-sectional average difference in the implied volatilities of at-the-money call and put equity options, is significantly and positively related to future stock market returns at daily, weekly, monthly, to semiannual horizons. This...

This paper investigates how institutional investors matter for asset pricing by using daily institutional trading data and a natural experiment, the split–share structure reform in China. This reform required all listed companies to convert their non-tradable shares to tradable shares after...

We provide simple examples to illustrate how wealth-driven selection works in asset markets. Our examples deliver both good and bad news. The good news is that if individual assets demands are expressed as a fractions of wealth to be invested in each asset, e.g. because traders maximize an...

We study the co-evolution of asset prices and individual wealth in a financial market populated by an arbitrary number of heterogeneous, boundedly rational agents. Using wealth dynamics as a selection device we are able to characterize the long run market outcomes, i.e. asset returns and wealth...

We consider an exchange economy with heterogeneous agents and multiple assets and investigate the coupled dynamics of assets' prices and agents' wealth. We assume that agents have heterogeneous beliefs and invest on each asset a fraction of wealth proportional to its expected dividends. Our main...

This paper studies whether, and to what extent, trading in an incomplete competitive market rewards the CAPM portfolio rule over alternative rules. We find that, if a mean-variance trader faces an agent who invests in each asset proportionally to expected relative payoffs, in the long-run only...

We build an equilibrium model to explain why stock return predictability concentrates in bad times. The key feature is that investors use different forecasting models, and hence assess uncertainty differently. As economic conditions deteriorate, uncertainty rises and investors' opinions...

We show how to conduct asymptotically valid tests of model comparison when the extent of model mispricing is gauged by the squared Sharpe ratio improvement measure. This is equivalent to ranking models on their maximum Sharpe ratios, effectively extending the GRS test to accommodate comparison...

In this paper I study the relationship between rationality and asset prices when agents have heterogeneous and incorrect beliefs about future events. Using the fully rational pricing as a benchmark, I show that when agents behave according to the Subjective Generalized Kelly rule (Bottazzi et...