We derive the equilibrium asset expected returns when there is ambiguity in asset expected returns, as well as ambiguity in asset return variances. In our model, ambiguity risk is systematic in nature and is non-diversifiable. Under regularity conditions, expected asset returns are linearly...

We examine whether commonality in liquidity arises from style investing. We sort stocks into styles along widely-used size and growth dimensions, and show that style-related commonality in liquidity is significant, dominates commonality in liquidity with the rest of the market, and has more than...

This paper is the second in a series of critiques of the assumption that stable economic relations exist between certain "firm characteristics" and expected returns. The paper explains why this is not the case for past returns and provides theoretical, empirical, and simulated evidence that the...

A risk-averse agent hedges her exposure to a non-tradable risk factor U using a correlated traded asset S and accounts for the impact of her trades on both factors. The effect of the agent's trades on U is referred to as cross-impact. By solving the agent's stochastic control problem, we obtain...

This paper tests the efficiency of macroeconomic forecasts, contributing to the existing literature using a rolling-event approach. We construct a monthly economic surprises index, aggregating several macroeconomic news surprises for the nine largest economic areas (G9), which we further analyze...

The paper aims at constructing an optimal portfolio by applying Sharpe's single index model of capital asset pricing in different scenarios, one is ex ante stock price bubble scenario and stock price bubble and bubble burst is second scenario. Here we considered beginning of year 2010 as rise of...

We explain the variability of the mean-variance efficient frontier over time with a statistical three factor model. For an asset universe consisting of 22 stocks listed in Switzerland, the model explains more than 99% of the time variations in the efficient frontier.The three factors can be...

Ever since Harry Markowitz published his seminal paper on portfolio selection, investors have incorporated estimates of future volatilities and correlations into their asset allocation process. While portfolio construction methods continue to evolve, many investors continue to forecast...

This paper presents three definitions of time diversification and analyzes their implications for investment horizons. Using decision quality criteria and methodology, we question standard advice. In analyzing time diversification with a minimum of assumptions, we answer two main questions: how...

Investors have different preferences for portfolio skewness and kurtosis, i.e. return asymmetry and tail fatness. We build up a new equilibrium model with three types of investors whose preferences can be characterized by "MV", "MVS" and "MVSK". (M: Mean V: Variance S: Skewness K: Kurtosis) and...