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Short Changed? The Market's Reaction to the Short Sale Ban of 2008


  • Louis Gagnon
  • Jonathan Witmer


Do short sales restrictions have an impact on security prices? We address this question in the context of a natural experiment surrounding the short sale ban of 2008 using a comprehensive sample of Canadian stocks cross-listed in the U.S. Among financial stocks, which were singled out by the ban in both countries, we observe a significant increase (74 bps) in the difference between the U.S. share price and the Canadian share price. We also observe an impressive and surprising migration of the trading volume from the U.S. to Canada among financial stocks during the ban. Both price and volume effects are reversed after the ban and neither effect manifests itself among the nonfinancial stocks. Our findings support the view that prices reflect a more optimistic valuation when pessimistic investors are kept out of the market by binding short-sales restrictions (Miller (1977)). Our findings also imply that pessimistic investors were more preponderant in the U.S. than in Canada, which is corroborated by the fact that the short interest ratio for our sample stocks was much larger in the U.S. than in Canada prior to the ban.

Suggested Citation

  • Louis Gagnon & Jonathan Witmer, 2009. "Short Changed? The Market's Reaction to the Short Sale Ban of 2008," Staff Working Papers 09-23, Bank of Canada.
  • Handle: RePEc:bca:bocawp:09-23

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    1. Michael J. Aitken & Alex Frino & Michael S. McCorry & Peter L. Swan, 1998. "Short Sales Are Almost Instantaneously Bad News: Evidence from the Australian Stock Exchange," Journal of Finance, American Finance Association, vol. 53(6), pages 2205-2223, December.
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    5. Karl B. Diether & Christopher J. Malloy & Anna Scherbina, 2002. "Differences of Opinion and the Cross Section of Stock Returns," Journal of Finance, American Finance Association, vol. 57(5), pages 2113-2141, October.
    6. Arturo Bris & William N. Goetzmann & Ning Zhu, 2007. "Efficiency and the Bear: Short Sales and Markets Around the World," Journal of Finance, American Finance Association, vol. 62(3), pages 1029-1079, June.
    7. Allen, Franklin & Gale, Douglas, 1991. "Arbitrage, Short Sales, and Financial Innovation," Econometrica, Econometric Society, vol. 59(4), pages 1041-1068, July.
    8. Hemang Desai & K. Ramesh & S. Ramu Thiagarajan & Bala V. Balachandran, 2002. "An Investigation of the Informational Role of Short Interest in the Nasdaq Market," Journal of Finance, American Finance Association, vol. 57(5), pages 2263-2287, October.
    9. Ackert, Lucy F. & Athanassakos, George, 2005. "The relationship between short interest and stock returns in the Canadian market," Journal of Banking & Finance, Elsevier, vol. 29(7), pages 1729-1749, July.
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    11. Andersen, Torben G & Bollerslev, Tim, 1998. "Answering the Skeptics: Yes, Standard Volatility Models Do Provide Accurate Forecasts," International Economic Review, Department of Economics, University of Pennsylvania and Osaka University Institute of Social and Economic Research Association, vol. 39(4), pages 885-905, November.
    12. Diamond, Douglas W. & Verrecchia, Robert E., 1987. "Constraints on short-selling and asset price adjustment to private information," Journal of Financial Economics, Elsevier, vol. 18(2), pages 277-311, June.
    13. Dechow, Patricia M. & Hutton, Amy P. & Meulbroek, Lisa & Sloan, Richard G., 2001. "Short-sellers, fundamental analysis, and stock returns," Journal of Financial Economics, Elsevier, vol. 61(1), pages 77-106, July.
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    Cited by:

    1. Bernal, Oscar & Herinckx, Astrid & Szafarz, Ariane, 2014. "Which short-selling regulation is the least damaging to market efficiency? Evidence from Europe," International Review of Law and Economics, Elsevier, vol. 37(C), pages 244-256.
    2. Fellner, Gerlinde & Theissen, Erik, 2014. "Short sale constraints, divergence of opinion and asset prices: Evidence from the laboratory," Journal of Economic Behavior & Organization, Elsevier, vol. 101(C), pages 113-127.
    3. repec:bla:acctfi:v:57:y:2017:i:3:p:727-757 is not listed on IDEAS
    4. Grundy, Bruce D. & Lim, Bryan & Verwijmeren, Patrick, 2012. "Do option markets undo restrictions on short sales? Evidence from the 2008 short-sale ban," Journal of Financial Economics, Elsevier, vol. 106(2), pages 331-348.
    5. Hasan, Iftekhar & Massoud, Nadia & Saunders, Anthony & Song, Keke, 2015. "Which financial stocks did short sellers target in the subprime crisis?," Journal of Banking & Finance, Elsevier, vol. 54(C), pages 87-103.

    More about this item


    Financial markets; International topics;

    JEL classification:

    • F30 - International Economics - - International Finance - - - General
    • G01 - Financial Economics - - General - - - Financial Crises
    • G18 - Financial Economics - - General Financial Markets - - - Government Policy and Regulation
    • G20 - Financial Economics - - Financial Institutions and Services - - - General

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