Managing a single portfolio is a basic assumption in the most of research. However, in reality, an advisor manages many accounts at the same time; therefore, there is a significant dependency among portfolios and correlation between decisions on one portfolio with the performance of others, so the results of multi portfolio is different with classic models (single portfolio management, that portfolios are optimized independently) due to market impact and the trade dependency of one account to the other accounts. We propose a structural model to optimize accounts simultaneously, considering interdependences, decision’s correlation and mutual behavioral effects of managed portfolios. Moreover, to compare and analyze both single portfolio and multi portfolio approaches, real data from Tehran Stock Exchange in 1398 are used and model is solved with GAMS. Results indicate that multi portfolio optimization excel other approach and consequence notable improvement on the perspective of customer and advisor. Also, for the validation of the proposed model, the selected stocks are considered in pairs to solve the model and the results show the proper performance of the model with different stocks, thus indicating the validity of the model. Manuscript profile

Using jumps in stock prices as a proxy for information shocks to examine investors' reactions to significant events is the most effective method for identifying information shocks. Compared to other studies, this method has advantages listed at the end of the literature review. We provide evidence consistent with short-term overreaction on the Tehran Stock Exchange. Thus, through the contrarian investment strategy, i.e., buying stocks with negative lagged jump returns and selling those with positive lagged jump returns, earn significantly positive returns over the next one- to three-month horizons. This research analyzed the adjusted daily closing prices of the top thirty stocks on the Tehran Stock Exchange in terms of market value and turnover during 2013-2020. Manuscript profile