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A Stock Price Predictive Model Based on Changes in Ratios of Short Interest to Trading Volume

Published online by Cambridge University Press:  19 October 2009

Mark Hanna
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The findings, based on price movements alone, are that trading on the assumption that a large (small) proportion of increases in stocks' short ratios is bullish (bearish) produced significantly better than expected results at all Alphas tested above .02. This test-by-predictiveness strongly supports the validity of the assumptions.

A test of the components of the short ratio produced no evidence that the success of the ratio as a stock market predictor can be attributed to either of its components singly, i.e., to either changes in short interest or changes in trading volume.

A second test of the assumptions incorporated in the SR Expectations Model consisted of a comparison of model results against buy-and-hold results. In all cases except at Alpha .01 model results exceeded buy-and-hold results–and greatly so at Alphas above .02, thus strongly supporting the validity of the assumptions.

The test against the buy-and-hold “control” standard was then extended to incorporate dividend and commission considerations. These considerations sharply reduced the model's performance. Therefore, an alternate strategy was tested which markedly reduced commissions, offset the opportunity cost of dividends missed when the portfolio was not long stocks, and avoided the explicit dividend drains caused by short positions. This strategy consisted of substituting Treasury Bill holdings for short positions in the basic model. This policy, consisting of switches between Treasury Bills and SSP “stocks” in accordance with Alpha .05 signals produced a terminal portfolio value greater than the buy-and-hold policy even after the introduction of a 30 percent income-tax consideration. Moreover, this higher return was generated with less risk than that inherent in the buy-and-hold policy.

With respect to the optimum filter, it was found that Alpha .11 was best for price predictive purposes, with Alpha .05 a close second, but that once commission considerations are allowed for, Alpha .05 was the optimum filter.

In conclusion, the hypothesis of this study is that when speculative expectations become extremely one-sided, a high probability exists that stock prices will reverse towards the unanticipated direction. This view is consistent with the theory that the stock market is generally efficient, but not perfectly so. A test of a model using changes in short ratios as a measure of shifts in investor expectations is consistent with the hypothesis: returns generated by the model significantly outperform random expectations. The test indicates a systematic tendency for investors to over-discount events when an overwhelming majority share the same optimism (pessimism) about future stock prices.

Type
Research Article
Information
Journal of Financial and Quantitative Analysis , Volume 11 , Issue 5 , December 1976 , pp. 857 - 872
Copyright
Copyright © School of Business Administration, University of Washington 1976

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References

REFERENCES

[1]Hanna, M. “Short Interest: Bullish or Bearish—Comment.” Journal of Finance (June 1968), pp. 520–523.Google Scholar
[2]Houthakker, H. S. “Normal Backwardation.” In Value, Capital and Growth Papers in Honour of Sir John Hicks, edited by Wolfe, J. N.. Chicago: Aldine Publishing Company, 1968, pp. 193–214.Google Scholar
[3]Kerrigan, T. J. “The Short Interest Ratio and Its Component Parts.” Financial Analyst Journal (November–December 1974), pp. 45–48.Google Scholar
[4]McDonald, J. G., and Baron, Donald C.. “Risk and Return on Short Positions in Common Stocks.” Journal of Finance (March 1973), pp. 97–107.CrossRefGoogle Scholar
[5]Lintner, J. “The Evaluation of Risk Assets and the Selection of Risky Investments in Stock Portfolios and Capital Budgets.” Review of Economics and Statistics (February 1965), pp. 13–37.Google Scholar
[6]Mayor, T. H. “Short Trading Activities and the Price of Equities: Some Simulation and Regression Results.” Journal of Financial and Quantitative Analysis (September 1968), pp. 283–298.Google Scholar
[7]Murphy, T. T., Ed. The New York Stock Exchange 1974 Fact Book. New York: New York Stock Exchange, 1974.Google Scholar
[8]Seneca, J. J. “Short Interest: Bearish or Bullish?” Journal of Finance (May 1967), pp. 67–70.Google Scholar
[9]Sharpe, W. F., and Cooper, G. M.. “Risk Return Classes of New York Stock Exchange Common Stocks, 1931–1967.” Financial Analyst Journal (March–April 1972), pp. 46–70.Google Scholar
[10]Smith, R. D. “Short Interest and Stock Market Prices.” Financial Analysts Journal (November–December 1968), pp. 151–154.Google Scholar
[11]Standard and Poor's Corporation. Daily Stock Price Record NYSE. New York, 1962–1973, Quarterly.Google Scholar
[12]Standard. Trade and Securities Statistics. Orange, Conn.: Standard and Poor's Corporation, 1974.Google Scholar
[13]Wiesenberger Services, Incorporated. Investment Companies. New York: Wiesenberger Services, Inc., 1961–1973.Google Scholar
[14]Zweig, M. E. “An Investor Expectations Stock Price Predictive Model Using Closed-End Fund Premiums.” Journal of Finance (March 1973), pp. 67–78.Google Scholar