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Yahoo! for Amazon: Sentiment Extraction from Small Talk on the Web


  • Sanjiv R. Das

    (Department of Finance, Leavey School of Business, Santa Clara University, Santa Clara, California 95053)

  • Mike Y. Chen

    (Ludic Labs, San Mateo, California 94401)


Extracting sentiment from text is a hard semantic problem. We develop a methodology for extracting small investor sentiment from stock message boards. The algorithm comprises different classifier algorithms coupled together by a voting scheme. Accuracy levels are similar to widely used Bayes classifiers, but false positives are lower and sentiment accuracy higher. Time series and cross-sectional aggregation of message information improves the quality of the resultant sentiment index, particularly in the presence of slang and ambiguity. Empirical applications evidence a relationship with stock values--tech-sector postings are related to stock index levels, and to volumes and volatility. The algorithms may be used to assess the impact on investor opinion of management announcements, press releases, third-party news, and regulatory changes.

Suggested Citation

  • Sanjiv R. Das & Mike Y. Chen, 2007. "Yahoo! for Amazon: Sentiment Extraction from Small Talk on the Web," Management Science, INFORMS, vol. 53(9), pages 1375-1388, September.
  • Handle: RePEc:inm:ormnsc:v:53:y:2007:i:9:p:1375-1388
    DOI: 10.1287/mnsc.1070.0704

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    References listed on IDEAS

    1. Bagnoli, Mark & Beneish, Messod D. & Watts, Susan G., 1999. "Whisper forecasts of quarterly earnings per share," Journal of Accounting and Economics, Elsevier, vol. 28(1), pages 27-50, November.
    2. Lo, Andrew W & MacKinlay, A Craig, 1990. "When Are Contrarian Profits Due to Stock Market Overreaction?," Review of Financial Studies, Society for Financial Studies, vol. 3(2), pages 175-205.
    3. David Godes & Dina Mayzlin, 2004. "Using Online Conversations to Study Word-of-Mouth Communication," Marketing Science, INFORMS, vol. 23(4), pages 545-560, June.
    4. N/A, 1996. "Note:," Foreign Trade Review, , vol. 31(1-2), pages 1-1, January.
    5. Werner Antweiler & Murray Z. Frank, 2004. "Is All That Talk Just Noise? The Information Content of Internet Stock Message Boards," Journal of Finance, American Finance Association, vol. 59(3), pages 1259-1294, June.
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