Investor behavior in the stock markets focusing on internet transactions

通过对融资融券交易者在标准化融资融券交易下的投资行为进行分析，我们发现融资融券交易的增加预示着未来股票价格的上涨。我们的发现表明，被认为是非理性交易者的个人投资者比其他投资者具有信息优势。这与过去文献中的发现完全相反。通过对日本和美国股票投资者的问卷调查，我们发现投资者预期的变化是导致20世纪90年代长期低迷的重要原因，美国90年代末的IT泡沫并非理性泡沫，进而我们考察了日本和中国股票价格的相互依赖关系，发现中国对日本存在单向因果关系；换句话说，中国的股票价格对日本的股票价格没有反应（Tsutsui和Hirayama， 2009）。

Focusing on the investment behavior of margin traders under the standardized margin transactions, we find that the increase in margin buying predicts the increase in future stock price. Our finding implies that individual investors, considered to be as irrational traders, have the information advantage over other investors. This is completely opposite to the findings in the past literature. As per the study on stock investors in Japan and the U. S. using questionnaire survey, we showed that change in investors' expectation played an important role in causing a long slump in 1990s and that the IT bubble in the U. S. in the late of 1990s was not a rational one, Furthermore, we investigated interdependencies of stock prices between Japan and China to find that there exists uni-directionally causality from China to Japan ; in other words, Chinese stock prices do not respond to those of Japan(Tsutsui and Hirayama, 2009).