We report that initial public offering (IPO) underpricing is positively related to analyst coverage by the lead underwriter and to the presence of an all‐star analyst on the research staff of the lead underwriter. These findings are robust to controls for other determinants of underpricing and to controls for the endogeneity of underpricing and analyst coverage. In addition, we find that the probability of switching underwriters between IPO and seasoned equity offering is negatively related to the unexpected amount of post‐IPO analyst coverage. These findings are consistent with the hypothesis that underpricing is, in part, compensation for expected post‐IPO analyst coverage from highly ranked analysts.

S&P 500 index funds represent one of the simplest vehicles for examining rational behavior. They hold virtually the same securities, yet their returns differ by more than 2 percent per year. Although the relative returns of alternative S&P 500 funds are easily predictable, the relationship between cash flows and performance is weaker than rational behavior would lead us to expect. We show that selecting funds based on low expenses or high past returns outperforms the portfolio of index funds selected by investors. Our results exemplify the fact that, in a market where arbitrage is not possible, dominated products can prosper.

This paper examines liquidity externalities by analyzing trading costs after hours. There is less than 1/20 as many trades per unit time after hours as during the trading day. The reduced trading activity results in substantially higher trading costs: quoted and effective spreads are three to four times larger than during the trading day. The higher spreads reflect greater adverse selection and order persistence, but not higher dealer profits. Because liquidity provision remains competitive after hours, the greater adverse selection and higher trading costs provide a direct measure of the magnitude of the liquidity externalities generated during the trading day.

When coupled with a stock's current price, a readily available piece of information—the 52‐week high price–explains a large portion of the profits from momentum investing. Nearness to the 52‐week high dominates and improves upon the forecasting power of past returns (both individual and industry returns) for future returns. Future returns forecast using the 52‐week high do not reverse in the long run. These results indicate that short‐term momentum and long‐term reversals are largely separate phenomena, which presents a challenge to current theory that models these aspects of security returns as integrated components of the market's response to news.

This paper examines short‐sales transactions in the five days prior to earnings announcements of 913 Nasdaq‐listed firms. The tests provide evidence of informed trading in pre‐announcement short‐selling because they reveal that abnormal short‐selling is significantly linked to post‐announcement stock returns. Also, the tests indicate that short‐sellers typically are more active in stocks with low book‐to‐market valuations or low SUEs. The levels of pre‐announcement short‐selling, however, mostly appear to reflect firm‐specific information rather than these fundamental financial characteristics. We believe that these results should encourage financial market regulators to consider providing more extensive and timely disclosures of short‐selling to investors.

A simple valuation model with time‐varying investment opportunities is developed and estimated. The model assumes that the investment opportunity set is completely described by the real interest rate and the maximum Sharpe ratio, which follow correlated Ornstein–Uhlenbeck processes. The model parameters and time series of the state variables are estimated using U.S. Treasury bond yields and expected inflation from January 1952 to December 2000, and as predicted, the estimated maximum Sharpe ratio is related to the equity premium. In cross‐sectional asset‐pricing tests, both state variables have significant risk premia, which is consistent with Merton's ICAPM.

We test overreaction theories of short‐run momentum and long‐run reversal in the cross section of stock returns. Momentum profits depend on the state of the market, as predicted. From 1929 to 1995, the mean monthly momentum profit following positive market returns is 0.93%, whereas the mean profit following negative market returns is −0.37%. The up‐market momentum reverses in the long‐run. Our results are robust to the conditioning information in macroeconomic factors. Moreover, we find that macroeconomic factors are unable to explain momentum profits after simple methodological adjustments to take account of microstructure concerns.