What Explains the Asset Growth Effect in Stock Returns?

Abstract

We consider the expanding evidence for a negative correlation between firm asset growth and subsequent stock returns with respect to two rational explanations: compensation for risk and costly arbitrage. We observe that the growth rate in total assets is the dominant asset growth rate variable in explaining the cross-section of stock returns. We show that a factor sensitivity to systematic asset growth does not generate a significant risk premium beyond the simple firm growth effect. We find that firm idiosyncratic volatility, which we use as a measure of the cost of holding a position in the stock per unit of time, explains substantial variation in the asset growth effect in the cross section of returns. Furthermore, time series patterns in alphas and factor loadings related to asset growth are associated with high idiosyncratic risk. Our findings highlight the magnitude of the impact of costly arbitrage on stock returns.