| The securities market of China has been existing almost30years, the total amounts of investors has been developed from a small amount to over100millions. And small investors have always been the most important partner of the securities market. Based on the behavior finance theory, by using the actual trading data of the small-medium stock market, this paper following does some systematic analysis of the self-attribution bias, such as the disposition effect, overconfidence and the overtrading behavior..Generally speaking, the disposition effect referring to investors prefer to selling the present profit stocks and holding the present loss ones, which maybe lose the chance of further making profit. And at the same time, those investors are too late to hold the present loss ones, it maybe bring the excess risk to the investors in the securities market. Overconfidence means that people are always overconfident on their judgments and overestimate their probability to deal with information, resulting that their stocks price from their own expectations, Is overtrading institution existing in China securities market, if the overconfidence psychological self-attribution bias exists among Chinese small investors? Overtrading situation referring to investors’ trade behavior is very frequent under the influnce of overconfidence, which leads to the high frequency transaction investors’ yield ratio lower than the low-frequency. This paper make a empirical analysis use the real transaction accounts data. Finally the paper draws the following conclusions:Firstly, the small investors of China securities market are inclined to sell the winning stocks while hold the losing stocks. Based on a calculation, the average probability for small investors to sell the winner is double of the loser.Secondly, the small investors hold the losing stocks longer than the losing stock, which is much clearer in a declining market, and all these prove that the small investors clearly have the disposition effect in China securities market.Thirdly, the yield ratio to buy stock is lower than to sell, which means that the process of investment decision exists overconfidence psychology. Actual investment income and the expected return do not be consistent.Fourthly, small investors of our securities market have a typical tendency to overtrade, and the transaction frequency of our securities market is higher than the investors of developed markets, which improved that psychological self-attribution bias exists among Chinese small investors.Lastly, the overtrading behavior of investor leads to the asset losses. Holding stock for a long time or reducing transaction frequency may have been a good way to raise yield ratio for small investors.Based on the conclusions, this paper takes some tentative suggestion in term of psychological training and supervision. |
