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On the Impossibility of Weak-Form Efficient Markets

Published online by Cambridge University Press:  06 April 2009

Steve L. Slezak
Steve L. Slezak
Affiliation:
slezaksl@ucmail.uc.edu, College of Business, University of Cincinnati, Carl H. Lindner Hall, PO Box 210195, Cincinnati, OH 45221–0195.
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Abstract

Recent theoretical models show that irrational expectations can generate return predictability consistent with apparent violations of weak-form market efficiency documented in the empirical literature. These behavioral models constrain rational investors' ability toexploit inter-temporal predictability by assuming that rational agents face high transactions costs, are myopic, or are non-existent. This paper presents a model in which there are two types of irrational expectations, one that causes momentum and another that creates reversals. I investigate whether these types of predictability will persist in the presence of fully rational agents who face no transactions costs, are long lived, and trade dynamically to optimally exploit any predictability due to irrational mispricings. I show that weak-form market efficiency will be violated under two very weak conditions: rational investors are risk averse and the fundamental value of the asset is risky. The paper also investigates the accumulation of wealth by trader type and shows that irrational agents will survive under a large set of parameters.

Type
Research Article
Information
Journal of Financial and Quantitative Analysis , Volume 38 , Issue 3 , September 2003 , pp. 523 - 554
Copyright
Copyright © School of Business Administration, University of Washington 2003

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References

Barberis, N.; Shleifer, A.; and Vishny, R.. “A Model of Investor Sentiment.” Journal of Financial Economics, 107 (1998), 797–817.Google Scholar
Bernard, V. L., and Thomas, J. K.. “Post-earnings-announcement Drift: Delayed Price Response or Risk Premium?” Journal of Accounting Research, Supplement, 27 (1989), 1–48.CrossRefGoogle Scholar
Bernard, V. L., and Thomas, J. K.. “Evidence That Stock Prices Do Not Fully Reflect the Implications of Current Earnings on Future Earnings.” Journal of Accounting and Economics, 13 (1990), 305–340.CrossRefGoogle Scholar
Blume, L., and Easley, D.. “Evolution and Market Behavior.” Journal of Economic Theory, 58 (1992), 9–40.CrossRefGoogle Scholar
Brav, A., and Heaton, J. B.. “Competing Theories of Financial Anomalies.” Review of Financial Studies, 15 (2002), 575–606.CrossRefGoogle Scholar
Conrad, J., and Kaul, G.. “An Anatomy of Trading Strategies.” Review of Financial Studies, 11 (1998), 489–519.CrossRefGoogle Scholar
Daniel, K. D.; Hirshleifer, D.; and Subrahmanyam, A.. “Investor Psychology and Security Market Under- and Over-reactions.” Journal of Finance, 53 (1998), 1839–1885.CrossRefGoogle Scholar
De Bondt, W. F. M., and Thaler, R. H.. “Does the Stock Market Overreact?” Journal of Finance, 40 (1985), 793–805.CrossRefGoogle Scholar
De Long, J. B.; Shleifer, A.; Summers, L.; and Waldmann, R. J.. “Positive Feedback Investment Strategies and Destabilizing Rational Speculation.” Journal of Finance, 45 (1990a), 379–395.CrossRefGoogle Scholar
De Long, J. B.; Shleifer, A.; Summers, L.; and Waldmann, R. J.. “Noise Trader Risk in Financial Markets.” Journal of Political Economy, 98 (1990b), 703–738.CrossRefGoogle Scholar
Gervais, S., and Odean, T.. “Learning to be Overconfident.” Review of Financial Studies, 14 (2001), 1–27.CrossRefGoogle Scholar
Grossman, S., and Stiglitz, J. E.. “On the Impossibility of Informationally Efficient Markets.” American Economic Review, 70 (1980), 393–408.Google Scholar
Grundy, B., and Martin, J. S.. “Understanding the Nature of the Risks and the Source of the Rewards to Momentum Investing.” Review of Financial Studies, 14 (2001), 29–78.CrossRefGoogle Scholar
Hong, H., and Stein, J. C.. “A Unified Theory of Underreaction, Momentum Trading, and Overreaction in Asset Markets.” Journal of Finance, 54 (1999), 2143–2184.CrossRefGoogle Scholar
Jegadeesh, N., and Titman, S.. “Returns to Buying Winners and Selling Losers: Implications for Stock Market Efficiency.” Journal of Finance, 48 (1993), 65–91.CrossRefGoogle Scholar
Kyle, A., and Wang, F. A.. “Speculation Duopoly with Agreement to Disagree: Can Over-Confidence Survive the Market Test?” Journal of Finance, 52 (1997), 2073–2090.CrossRefGoogle Scholar
Lo, A., and MacKinlay, C.. “When Are Contrarian Profits Due to Stock Market Overreaction?” Review of Financial Studies, 3 (1990), 175–206.CrossRefGoogle Scholar
Loughran, T., and Ritter, J.. “The Operating Performance of Firms Conducting Seasoned Equity Offering.” Journal of Finance, 52 (1997), 1823–1850.CrossRefGoogle Scholar
Luo, G. Y. “Market Efficiency and Natural Selection in a Commodity Futures Market.” Review of Financial Studies, 11 (1998), 647–674.CrossRefGoogle Scholar
Odean, T. “Volume, Volatility, Price, and Profit when All Traders Are above Average.“” Journal of Finance, 53 (1998), 1887–1934.CrossRefGoogle Scholar
Richardson, M. “Temporary Components of Stock Prices: A Skeptic's View.” Journal of Business and Economic Statistics, 11 (1993), 199–207.CrossRefGoogle Scholar
Shleifer, A., and Vishny, R. W.. “The Limits of Arbitrage.” Journal of Finance, 52 (1997), 35–55.CrossRefGoogle Scholar
Slezak, S. L. “A Theory of the Dynamics of Security Returns around Market Closures.” Journal of Finance, 49 (1994), 1163–1211.CrossRefGoogle Scholar