中文摘要：

本文利用深圳证券交易所所有投资者账户信息和交易信息，基于财富水平，将个人投资者分为小个人组、中个人组和大个人组三类，在此基础上，研究分类个人投资者和机构投资者的交易行为。结果显示，小个人组的交易行为左右了个人总体的行为，而中个人组和大个人组的行为与机构极其相似；小个人组和个人总体在买入时，从短期来看采用反转策略，从长期来看采用动量策略，卖出时均采用反转策略；中个人组、大个人组和机构无论从长期还是短期来看，在买入时都采用反转策略，卖出时都采用动量策略。同时我们发现，小个人组趋于非理性，是风险偏好型投资者，具有损失厌恶心理，并且存在处置效应和周内效应；而中个人组、大个人组和机构投资者是风险厌恶型投资者。

英文摘要：

Based on all investors＇ accounts and trading intormation in Shenzhen Stock Exchange, the paper studies the trading behaviors and strategies of individual and institutional investors. The result shows that although the small group of individuals controlled the individual trading behaviors and strategies, the middle group and the large group were behaving in the quite same way with the institution. The small group took momentum strategy in the long term for buying and contrarian strategy in all period for selling. The others took contrarian strategy in buying and momentum strategy in selling. It also found that small group were risk-seeking investors and reluctant to realize loss, and they had disposition effect and weekly effect. However, the others are risk aversion investors.