Knowledge that Transforms

David Heath, Robert Jarrow, Andrew Morton, Bond Pricing and the Term Structure of Interest Rates: A Discrete Time Approximation, The Journal of Financial and Quantitative Analysis, Vol. 25, No. 4 (Dec., 1990), pp. 419-440

Recent research finds that the prior period's worst stock return performers (losers) outperform the prior period's best return performers (winners) in the subsequent period. This potential violation of the efficient markets hypothesis is labeled the “overreaction” phenomenon. This paper shows that the tendency for losers to outperform winners is not due to investor overreaction, but to the tendency for losers to be smaller-sized firms than winners. When losers are compared to winners of equal size, there is little evidence of any return discrepancy, and in periods when winners are smaller than losers, winners outperform losers.

Anup Agrawal, Gershon N. Mandelker, Large Shareholders and the Monitoring of Managers: The Case of Antitakeover Charter Amendments, The Journal of Financial and Quantitative Analysis, Vol. 25, No. 2 (Jun., 1990), pp. 143-161

Most asset pricing models postulate a positive relationship between a stock portfolio's expected returns and risk, which is often modeled by the variance of the asset price. This paper uses GARCH in mean models to examine the relationship between mean returns on a stock portfolio and its conditional variance or standard deviation. After estimating a variety of models from daily and monthly portfolio return data, we conclude that any relationship between mean returns and own variance or standard deviation is weak. The results suggest that investors consider some other risk measure to be more important than the variance of portfolio returns.

In rational, efficiently functioning markets, the returns on stock index and stock index futures contracts should be perfectly, contemporaneously correlated. This study investigates the time series properties of 5-minute, intraday returns of stock index and stock index futures contracts, and finds that S&P 500 and MM index futures returns tend to lead stock market returns by about five minutes, on average, but occasionally as long as 10 minutes or more, even after stock index returns have been purged of infrequent trading effects; however, the effect is not completely unidirectional, with lagged stock index returns having a mild positive predictive impact on futures returns.