U.K. and U.S. trading of British cross-listed stocks: an intraday analysis of market integration

This article analyzes intraday patterns for U.K. and U.S. tradingof British cross-listed stocks. For each market, the intradaypatterns for these stocks closely resemble those of otherwisesimilar, non-cross listed stocks. There is a 2-hour period eachday when cross-listed stocks are traded both in New York andin London. This overlap is characterized by concentrated tradingas private information, originating in New York, gets incorporatedinto prices in both markets. Cross-border competition for orderflowtends to reduce already declining spreads in London. By contrast,New York specialists maintain     

Trading volume: definitions, data analysis, and implications of portfolio theory

We examine the implications of portfolio theory for the cross-sectionalbehavior of equity trading volume. Two-fund separation theoremssuggest a natural definition for trading activity: share turnover.If two-fund separation holds, share turnover must be identicalfor all securities. If (K + 1)-fund separation holds, we showthat turnover satisfies an approximately linear K-factor structure.These implications are examined empirically using individualweekly turnover data for NYSE and AMEX securities from 1962to 1996. We find strong evidence against two-fund separation,and a principal-components decomposition suggests that turnoveris well approximated by a two-factor linear model.     

When are contrarian profits due to stock market overreaction?

If returns on some stocks systematically lead or lag those ofothers, a portfolio strategy that sells 'winners' and buys 'losers'can produce positive expected returns, even if no stock's returnsare negatively autocorrelated as virtually all models of overreactionimply. Using a particular contrarian strategy we show that,despite negative autocorrelation in individual stock returns,weekly portfolio returns are strongly positively autocorrelatedand are the result of important cross-auto-correlations. Wefind that the returns of large stocks lead those of smallerstocks, and we present evidence against overreaction as theonly source of contrarian profits.     

Perspectives on Michael A. Bernstein's A Perilous Progress: Economists and Public Purpose in Twentieth-Century America *

The article compares Joseph Schumpeter's well-known perspectives of long term economic development with those put forward in the 1920's by the German economist Werner Sombart who followed an approach of ‘theoretical historicism’. There was general agreement between Schumpeter and Sombart that capitalism as an economic system was on the decline. Whereas according to Sombart this was attributable to a tendancy towards stagnation; in Schumpeter's view capitalism was doomed due to its success, not for its failure. The strongest parallels are to be found with respect to forces driving the transformation process, at the end of which Schumpeter expected a socialist system whereas Sombart envisioned some kind of mixed economy. The article also discusses the relevance of differences of approaches and of value judgments for the results of both authors' investigations.     

Underestimation of portfolio insurance and the crash of October 1987

We examine market crashes in the multiperiod framework of Glostenand Milgrom (1985). Our analysis shows that if the market'sprior beliefs underestimate the extent of dynamic hedging strategiessuch as portfolio insurance, then the price will be greaterthan that which would be implied by fundamentals if the extentof portfolio insurance were known with certainty. Over time,the market learns of the amount of portfolio insurance, andconsequently reevaluates the previous inferences drawn frompurchases that were erroneously regarded as based on favorableinformation. The result is that the price falls when the amountof portfolio insurance is revealed.     

Index-futures arbitrage and the behavior of stock index futures prices

This article examines intraday transaction data for S&P500 stock index futures prices and the intraday quotes for theunderlying index. The data indicate that the futures price changesare uncorrelated and that the variability of these price changesexceeds the variability of price changes in the S&P 500index. This excess variability of the futures over the indexremains even after controlling for the nonsynchronous pricesin the index quotes, which induces auto-correlation in the indexchanges. We advance and examine empirically two hypotheses regardingthe difference between the futures price and its theoreticalvalue: that this 'mispricing' increases on average with maturity,and that it is path-dependent. Evidence supporting these hypothesesis presented.     

Asset pricing models: implications for expected returns and portfolio selection

When a risk factor is missing from an asset pricing model, theresulting mispricing is embedded within the residual covariancematrix. Exploiting this phenomenon leads to expected returnestimates that are more stable and precise than estimates deliveredby standard methods. Portfolio selection can also be improved.At an extreme, optimal portfolio weights are proportional toexpected returns when no factors are observable. We find thatsuch portfolios perform well in simulations and in out-of-samplecomparisons.