Advances in Mathematical Finance and Application (AMFA)

How the investors react to the received information plays a crucial role in determining the return of stock exchange market. Supply and demand based upon incorrect decisions lead to the price deviation of inherent values. This paper aims to study the impact of salience phenomenon on disproportionate pricing and investor overreaction in the corporates in Tehran stock exchange. Research methodology is correlative. Statistical sample involves 120 corporates accepted by Tehran stock exchange during 2012-2016. To test the hypotheses, a regression analysis method has been selected. Research findings have indicated that there exists a promising phenomenon in Tehran stock exchange causing the investors overreaction followed by the disproportionate pricing and also, the results have shown that the impact of salience is different on strong and weak information environments.

The purpose of this study was to determine the effect of financial distress on investment behavior for the years of 2011 to 2016. The statistical population of the research is Tehran Stock Exchange. According to the systematic elimination method, 104 companies have been selected as the statistical sample. In this research, financial distress is independent variable and corporate investment behavior is dependent variable and investment opportunities is considered as interactive variable. The present research is an applied research and in terms of methodology is a correlational study. In this research, for collecting data and information, library method and in the research data section, financial statements, explanatory notes and monthly magazine of stock exchange, and in order to describe and print the data collected, descriptive and inferential statistics and to analyze the data, pre-test variance analysis, F-limmer test, Hausman test and Jarck-Bera test, and then multivariate regression test for confirmation and rejection of research hypotheses (EViews software) were used. The results showed that firms with less investment opportunities tend to be less likely to invest, in addition distressed financially firms with more investment opportunities are more likely to increase investment.

Investment in renewable energies especially solar energies is encountered with numerous uncertainties considering the increased dynamism in economic and financial conditions and makes investment in this field irreversible to a large extent, paying attention to modern methods of economic appraisal of such investments is highly important. A framework is provided in the current study in order to employ the real option theory in evaluation of photovoltaic plants comparing with traditional methods. To this end, first, uncertainty factors of these plants in Isfahan province (one of highly susceptible regions in Iran) are identified from the view point of experts and impact factor of each one on interests and expenses of the above plant will be evaluated in order to insert these parameters in the form of fuzzy numbers in the model for better coverage of uncertainty. Then, the project under study is evaluated through both traditional methods and fuzzy real option approach with the help of Black-Scholes model and the results are compared. The results disclosed that investment value in these plants is increased if real expansion and abandonment options are considered. As a result, the real option theory has a higher adequacy than the traditional methods for evaluation of projects.

The facility interest rate is one of the most important macroeconomic variables. The bank facility interest rate is associated with other macro-economic variables, one of which is the bank deposit interest rate. Using the time series data of the 1973-2017 period and the simultaneous equation system, the researchers estimated four equations using the three-stage least squares method.The result of estimation of the first equation indicates that there is a significant positive relationship between the bank deposit interest rate and the facility interest rate in the Iranian economy during this 45-year period, in that a decrease in the facility interest rate follows an increase in the inflation rate.The result of estimation of the second equation, in which the deposit interest rate is the dependent variable, shows that there is a significant positive relationship between the facility interest rate and the deposit interest rate.. The result of estimation of the third equation, where the inflation rate is the dependent variable, indicates that there is a significant positive relationship between the liquidity level and the inflation rate,The result of estimation of the last equation where the credit risk of banks is the dependent variable shows that there is a significant positive relationship between the facility interest rate and the credit risk.

Stock market is affected by news and information. If the stock market is not efficient, the reaction of stock price to news and information will place the stock market in overreaction and under-reaction states. Many models have been already presented by using different tools and techniques to forecast the stock market behavior. In this study, the reaction of stock price in the stock market was modeled by the behavioral finance approach. The population of this study included the companies listed on the Tehran Stock Exchange. In order to forecast the stock price, the final price data of the end December, March, June, and September 2006-2015 and the stock prices of 2014 and 2015 were analyzed as the sample. In this study, Bayes' rule was used to estimate the probability of the model change. Through this rule, the probability of an event can be calculated by conditioning the occurrence or lack of occurrence of another event. The results of model estimation showed that there is the probability of being placed in high-fluctuated regimes (overreaction) and low- fluctuated (under-reaction of stock price despite the shocks entered to the stock market. In modelling with the 4-month final prices, it was proved that the real stock price had no difference from the market price.

According to the firm life cycle theory, companies go through certain behavioral patterns in various stages of their life. A thorough understanding and recognition of these behavioral patterns, new investment in assets and the optimal use of assets can considerably enhance the capital productivity. In the current study, the relationship between the stages of firm life cycle and capital productivity and mediation relationship of the capital investment choice in the two groups of companies have been examined, and methodically compared and contrasted. To examine the research hypothesis, the data were gathered from 118 companies accepted in Tehran Stock Exchange during a period of 7 years. Findings of the research clearly indicated that there is a positive relationship between introduction, growth and maturity stages with capital productivity in the cyclical and non-cyclical companies. Regarding the cyclical companies, a positive relationship was witnessed between the decline stage and capital productivity. Such a relation, however, was not found between the two variables in non-cyclical companies. Also, no significant relationship was observed among the stages of introduction, growth, maturity and the capital investment choice in both groups of companies. In non-cyclical companies, the relationship between the decline stage and the capital investment choice was positive, while there was no relationship between cyclical companies. Capital investment choice also failed to prove the assumed mediating role.

Modern portfolio theory is based on the relationship between risk and return and in this paper, specific uncertainty conditions are introduced as ambiguity which affects the asset pricing. Also, the relationship between risk, ambiguity and return is examined. First, ambiguity is estimated by the means of three-variable and main component method, trading volume, ask-bid spread, error of earnings forecast and afterwards, it has been used to examine the interaction between risk, ambiguity and return. Current research method is correlative descriptive and statistical sample consisted of 120 corporates accepted in Tehran Stock Exchange during 2012-2017. To test the hypotheses, regression analysis has been utilized. Results revealed the existence of ambiguity in Tehran Stock Exchange, which affects the asset pricing negatively

Recent studies show that individual investors tend to speculate on stock markets and hold shares with a lottery-like return. For this speculation of people have a significant impact on stock returns, individual investors must trade the same shares with the same time. The purpose of this study was to investigate the effect of the speculative bubble on the stock returns of companies in Iran. Following the design of the speculative bubble specification indexes, the transaction information was collected from the stock market in the five-year period from 2011 to 2015 and a sample of 106 companies was selected by systematic elimination method, which totaled 530 year-company. In this research, linear regression and correlation analysis were used to analyze the hypotheses of the research. To analyze the data and test the hypotheses, Eviews software was used. What can be said in the summing-up and conclusion of the general test of research hypotheses is that there is a speculative bubble in the Tehran Stock Exchange index. In addition, the speculative bubble has an impact on stock returns, and this effect has been confirmed in conditions of market boom and downswing. The results obtained in this study are consistent with the documents referred to in the theoretical framework of the research and financial literature.