中文摘要：

以某证券营业部622425条个人投资者交易记录数据为基础，分析盈余公告日后个人投资者的实际交易行为与未预期盈余的关系，检验个人投资者与PEAD的关系，探讨个人投资者是否是驱动盈余公告后漂移的原因。研究发现，无论未预期盈余为正或为负，个人投资者均没有表现出显著的买入或者卖出行为，且个人投资者的行为也无助于市场收益的预测，拒绝了个人交易假说。因此，个人投资者的交易行为并不是盈余公告后漂移的原因。

英文摘要：

Based on 622 425 trading records in a retail broker, the paper studies the relationship between individual investors＇ actual trading behaviors and post earnings announcement drift （PEAD） , tests the relationship between the individual investor and PEAD, and analyzes whether individual investors＇ trading behaviors are reasons for PEAD. Results show that individual investors do not have significant purchasing or selling behavior whether unexpected earnings are positive or not, individual investors＇ behaviors contribute nothing to predicting the market return, and hence the individual trading hypothesis is rejected. As a conclusion, individual investors＇ trading behaviors are not reasons for PEAD.