We document the equity trading practices of approximately 1,200 institutions from the third quarter of 1987 through the third quarter of 1995. We decompose trading by institutions into the initiation of new positions (entry), the termination of previous positions (exit), and adjustments to ongoing holdings. Institutions act as momentum traders when they enter stocks but as contrarian traders when they exit or make adjustments to ongoing holdings. We find significant differences in trading practices among different types of institutions.

ABSTRACT Most term structure models assume bond markets are complete, that is, that all fixed income derivatives can be perfectly replicated using solely bonds. How ever, we find that, in practice, swap rates have limited explanatory power for returns on at‐the‐money straddles—portfolios mainly exposed to volatility risk. We term this empirical feature unspanned stochastic volatility (USV). While USV can be captured within an HJM framework, we demonstrate that bivariate models cannot exhibit USV. We determine necessary and sufficient conditions for trivariate Markov affine systems to exhibit USV. For such USV models, bonds alone may not be sufficient to identify all parameters. Rather, derivatives are needed.

ABSTRACT This paper examines the relationship between the level of short interest and stock returns in the Nasdaq market from June 1988 through December 1994. We find that heavily shorted firms experience significant negative abnormal returns ranging from −0.76 to −1.13 percent per month after controlling for the market, size, book‐to‐market, and momentum factors. These negative returns increase with the level of short interest, indicating that a higher level of short interest is a stronger bearish signal. We find that heavily shorted firms are more likely to be delisted compared to their size, book‐to‐market, and momentum matched control firms.

Public firms that place equity privately experience positive announcements effects, with negative post‐announcement stock‐price performance. This finding is inconsistent with the underreaction hypothesis. Instead, it suggests that investors are overoptimistic about the prospects of firms issuing equity, regardless of the method of issuance. Further, in contrast to public offerings, private issues follow periods of relatively poor operating performance. Thus, investor overoptimism at the time of private issues is not due to the behavioral tendency to overweight recent experience at the expense of long‐term averages.