The heavy-tailed distribution of firm sizes first discovered by Zipf (1949) is one of the best established empirical facts in economics. We show that it has strong implications for asset pricing. Due to the concentration of the market portfolio when the distribution of the capitalization of...

We provide evidence that trading frictions have an economically important impact on the execution and the profitability of option strategies that involve writing out-of-the-money put options. Margin requirements, in particular, limit the notional amount of capital that can be invested in the...

This paper studies the ICAPM intertemporal relation between the conditional mean and the conditional variance of the aggregate stock market return. We introduce a new estimator that forecasts monthly variance with past daily squared returns -- the Mixed Data Sampling (or MIDAS) approach. Using...

This paper offers a new approach for pricing options on assets with stochastic volatility. We start by taking as given the prices of a few simple, liquid European options. More specifically, we take as given the “surface†of Black-Scholes implied volatilities for European options with...

We propose a novel approach to optimizing portfolios with large numbers of assets. We model directly the portfolio weight in each asset as a function of the asset’s characteristics. The coefficients of this function are found by optimizing the investor’s average utility of the...

We find that the average excess return in the stock market is higher under Democratic than Republican presidents– a difference of 9 percent per year for the value-weighted portfolio and 16 percent for the equal-weighted portfolio. The difference is economically and statistically...

We investigate the risk and return of a wide variety of trading strategies involving options on the S&P 500. We consider naked and covered positions, straddles, strangles, and calendar spreads, with different maturities and levels of moneyness. Overall, we ï¬nd that strategies involving short...