Evaluating Market Risk Assessment through VAR Approach before and after Financial Crisis in Tehran Stock Exchange Market (TSEM)

摘要

the goal of the present research is to evaluate the performance of 4 models of assessing value at risk, namely Simple VaR, Risk Metric VaR, GARCH (1,1), and GJR-GARCH in the way to introduce the most reliable one to be used under special circumstances of financial crisis. The method used in order to do so has been the volatilities of the all share index and those of the industrial index in TSEM between 2003 and 2013 were employed. In order to elicit points of crisis in the aforementioned span of time, partial regression was employed. The findings indicated 3 points of crisis; the two more recent ones, the ones in 2009 and 2012, were chosen. For each period of crisis, the data on the period between this target crisis and the one beforehand was used so to estimate models. In addition, the data between the target crisis and the one afterwards was employed so to validate the models. Validation tests for the models were carried out at three confidence levels of 95%, 97.5%, and 99%, using Cupic, Christopherson, and Lopez tests. The findings indicated that the models employed for the study have a desirable level of ability at predicting market risk in the periods of crisis. In addition, the findings of testing minor hypotheses of the study showed that parallel to increasing level of confidence for the models, GARCH (1,1) has a better performance in comparison to VaR model. The present paper aimed at measuring market risk which has been one of the basic goals of TSEM. This supports the cause of carrying out this study. In addition to this, investors in the market, too, would support carrying this study as necessary. It is claimed in this article that simple VaR, Simple GARCH, and GJR-GARCH are useful to predict risk of the market under financial crisis circumstances.