This paper employs recent developments in agency theory to study the impact that compensation contracts have on portfolio management investment decisions in a restricted mean-variance world. Two types of incentive contracts for mutual fund managers are analyzed and compared. The results show that the “symmetric” contract, while not necessarily eliminating agency costs, dominates the “bonus” contract in aligning the manager's interests with those of the investor.

According to the Diamond-Verrecchia hypothesis, if increases in short interest are correlated with information that is not yet public, they should precipitate a price adjustment. Stocks with unexpected increases in short interest are found to generate statistically significant, but small, negative abnormal returns for a short period around the announcement date. When the sample is divided into stocks with and without tradable options, nonoptioned stocks closely mimic these results but the optioned stocks do not. In a cross-sectional analysis of individual firms, the short-term negative abnormal returns are found to be 1) more negative, the higher the degree of unexpected short interest and, 2) less negative if the firm has tradable options.