دکتر ناصر جمشیدی

The aim of this study is to investigate the behavior of individual and institutional investors in Tehran Stock Exchange. For this purpose, we examined the portfolio statement of individual and institutional investors during a five-year period from 2012 to 2016. The result show that Investors’ behavior reflects some behavioral biases. Specifically, both individual and institutional investors tend to sell stocks that have appreciated in price, but not those that have depreciated in price (consistent with a disposition effect), although this tendency is more for individual investors. They also appear to believe that past returns are indicative of future returns (a representativeness bias), and their trading behavior shows that they are overconfidence. In the following, to investigate the effect of characteristics of investors on the cognitive errors, behavioral biases and trading error are investigated based on characteristics of investors.

This research examines the overconfidence, representativeness and disposition effect biases among individual investors of the Tehran Stock Exchange. The purpose of this research is to investigate the extent to which these biases are prevalent among investors and their relation with investors' performance. 

For this purpose, we examined the portfolio statements of individual investors in the stock market during a five-year period, from 2012 to 2016. We have used multiple indicators to measure the behavioral bias and to examine the relationship between behavioral bias and investors' performance by the portfolio study method. 

The results show that overconfidence, representativeness and disposition effect are relatively prevalent among investors. There is also a significant relationship between the overconfidence and representativeness biases and the performance of investors, although this relationship is not significant for the disposition effect. Specifically, investors with a higher portfolio turnover, as well as a more concentrated portfolio, have earned higher returns. Also, investors who bought past winning stocks have had higher average returns.

Behavioral bias is relatively common among investors, and these biases can affect the performance of the investors.

The purpose of this research is to compare the performance of investors who are actively involved in stock transactions with other investors’. For this purpose, examining the portfolio statement of investors in Tehran Stock Exchange during the five-year period from 2012 to 2016, we have also adopted two analytical approaches. First, through the Portfolio Study Method, the monthly returns of investors with a high portfolio turnover rate (active investors) have been compared with that of investors with low portfolio turnover rate (passive investors). Second, using a complementary approach (called Own-Benchmark Abnormal Return), we have examined investors’ monthly returns in two different modes: 1.changing the composition of the portfolio; 2.maintaining the primary composition of the portfolio. The results show investors with a higher trading frequency, both before and after the deduction of transaction costs, have a better performance than other investors. Also, the performance of investors in the first mode is better than in the second mode.

To date, the main source of inspiration for behavioral finance scholars has been cognitive psychology. This study builds on this tradition by merging in insights from yet another psychological sub-discipline: personality psychology. We argue that a human being’s personality is a key determinant of his/her behavior and performance. We illustrate, for a subset of five personality traits (locus of control, maximizing tendency, self-monitoring, sensation seeking and type-A/B behavior), how this logic can be applied in the context of the study of traders’ behavior and performance.
we investigated the behavioral and functional components of 380 individual investors in the stock market using survey method and collecting the questionnaire.
The results suggested that Investors with an external locus of control, type-A behavior and high maximizing tendency are busy working on trading more frequently. Investors with an external locus of control, high sensation seeking and high self-monitoring have a less diverse portfolio. Finally, the frequency of transactions is related to better performance, while portfolio diversification does not affect the performance of the individuals.
Different personality traits affect distinct components of trading behavior, and so trading performance.