The present study deals with the importance of influencing factors on the popular behavior of individual investors in the Iranian capital market based on the interpretive structural modeling approach and its purpose is to help managers of stock exchange mutual funds in making correct financial decisions. It has been done by making them aware of these behavioral factors. In order to identify the factors affecting the popular behavior of individual investors, relevant experts, and professors have been used. The present study was an applied-research. The statistical population of this research is limited in refining the factors affecting this behavior, including experts, professors, and experts, as well as in choosing the optimal capital mix of investors in the Tehran Stock Exchange. The research method is based on the factors identified from research sources that have been approved by experts and experts using the fuzzy Delphi method, and they are introduced in the period from 2016 to 2021. The findings of the research showed that the fourth level, related to the exchange rate, has the greatest impact on the popular behavior of individual investors in the Iranian capital market. Based on the results, it can be said that due to the fact that investors know more about the more traded shares, the probability of this behavior in buying and selling these shares has decreased. In fact, conducting more transactions has caused the release of more information and this information has prevented the formation of popular-like behavior.