Traditional risk factor models indicate that hedge funds capture pre‐fee alphas of 6% to 10% per annum over the period from 1996 to 2012. At the same time, the hedge fund return series is not reliably distinguishable from the returns of mechanical S&P 500 put‐writing strategies. We show that the high excess returns to hedge funds and put‐writing are consistent with an equilibrium in which a small subset of investors specialize in bearing downside market risks. Required rates of return in such an equilibrium can dramatically exceed those suggested by traditional models, affecting inference about the attractiveness of these investments.

This paper examines the trading behavior of professional investors around 2,130 mergers announced between 1994 and 2000. We find considerable support for the existence of price pressure around mergers caused by uninformed shifts in excess demand, but that these effects are short‐lived, consistent with the notion that short‐run demand curves for stocks are not perfectly elastic. We estimate that nearly half of the negative announcement period stock price reaction for acquirers in stock‐financed mergers reflects downward price pressure caused by merger arbitrage short selling, suggesting that previous estimates of merger wealth effects are biased downward.

We examine 82 situations where the market value of a company is less than its subsidiary. These situations imply arbitrage opportunities, providing an ideal setting to study the risks and market frictions that prevent arbitrageurs from immediately forcing prices to fundamental values. For 30 percent of the sample, the link between the parent and its subsidiary is severed before the relative value discrepancy is corrected. Furthermore, returns to a specialized arbitrageur would be 50 percent larger if the path to convergence was smooth rather than as observed. Uncertainty about the distribution of returns and characteristics of the risks limits arbitrage.

This paper models transaction costs as the rents that a monopolistic market maker extracts from impatient investors who trade via limit orders. We show that limit orders are American options. The limit prices inducing immediate execution of the order are functionally equivalent to bid and ask prices and can be solved for various transaction sizes to characterize the market maker's entire supply curve. We find considerable empirical support for the model's predictions in the cross‐section of NYSE firms. The model produces unbiased, out‐of‐sample forecasts of abnormal returns for firms added to the S&P 500 index.