In this paper, we infer how the estimates of firm value by “optimists” and “pessimists” evolve in response to information shocks. Specifically, we examine returns and disagreement measures for portfolios of short-sale-constrained stocks that have experienced large gains or large losses. Our analysis suggests the presence of two groups, one of which overreacts to new information and remains biased over about 5 years, and a second group, which underreacts and whose expectations are unbiased after about 1 year. Our results have implications for the belief dynamics that underlie the momentum and long-term reversal effect.

中文翻译：

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分歧的动态

在本文中，我们推断“乐观主义者”和“悲观主义者”对公司价值的估计如何随着信息冲击而演变。具体来说，我们研究了经历过大收益或大损失的卖空受限股票投资组合的回报和分歧度量。我们的分析表明存在两组，其中一组对新信息反应过度，并且在大约 5 年内仍然存在偏见，另一组反应不足，并且其预期在大约 1 年后没有偏见。我们的结果对构成动量和长期逆转效应的信念动态有影响。