Overconfidence and Investor Size
利用芬兰全面交易数据，研究发现投资者规模影响其对新闻的反应：大投资者对好消息反应更积极、对坏消息更消极，而小投资者因过度自信表现受损。
Abstract Recent research documents that institutional or large investors act as antagonists to other investors by showing opposite trading behaviour following the disclosure of new information. Using an extremely comprehensive official transactions data set from Finland, we set out to explore the interrelation between investor size and behaviour. More specifically, we test whether investor size is positively (negatively) correlated with investor reaction following positive (negative) news. We document robust evidence of that investor size affects investor behaviour under new information, as larger investors on average react more positively (negatively) to good (bad) news than smaller investors. We furthermore find that the performance of smaller, or more overconfident, investors is in general hurt by their behaviour.