مرتضی فرهادی سرتنگی

Markets such as Money Market, Labor market, Commodity market along with Capital market are committed to optimal allocation of capital and financial resources. One of the most important sources of information is financial reports. Investors base their decisions on the balance between risk and return and are interested in estimating their expected future returns and investments using information reported by the company and other evidence. The purpose of this study is to investigate the relationship between accounting conservatism and cost of equity capital and evaluate the economic results of accounting conservatism through information perspective. Therefore, in order to achieve the main objective of the research, first the reports and documentation of past performance of the sample member companies have been studied and the required data have been collected. The research hypotheses were then evaluated which consisted of one main hypothesis and two sub-hypotheses, indicating that there is a negative and relatively strong relationship between conserv-atism and capital cost. Differentiating between several aspects of accounting con-servatism and examining the relationship among each aspect and cost of equity capital are new innovation of the present study. .

Study of volatility has been considered by the academics and decision makers dur-ing two last decades. First since the volatility has been a risk criterion it has been used by many decision makers and activists in capital market. Over the years it has been of more importance because of the effect of volatility on economy and capital markets stability for stocks, bonds, and foreign exchange markets. This research first deals with the evaluation of 8 various models to forecasting volatility of stock index using daily data of Tehran stock exchange. The used models include simple ones such as random walk as well as more complex models like Arch and Garch group. Forecasting volatility index method is developed in this paper. This method is based a random walk using a fuzzy logic approach. This method is used to fore-casting volatility of Iran stock exchange index. The proposed method is assessed by comparing other methods such as Moving Average, Random walk… Results show that our proposed method is compatible with existent methods.