Spread plays essential role on market liquidity on any stock market. A high gap between bid and ask price may reduce the likelihood of trading activities while a small gap between bid and ask increases the chance of trade execution. In this paper, we present an empirical investigation on the effect of spread on abnormal return. The proposed study collects the necessary information from official statements as well as historical data over the period 2009-2013 reported on Tehran Stock Exchange to examine the relationship between spread and unusual firm performance. Using regression analysis, the study has determined a meaningful relationship between abnormal return and spread.

In this study, we examine the relationship between GDP, export, import, private sector investment and inflation on insurance per capita of OPEC countries. Insurance is a non-banking institution that by making sure and secure, can make and develop manufacturing and service rendering easier. Insurance companies can make financial steady and reduce stress. So, it plays essential role in economy. For this aim, data over the period 2003-2011 is collected. We use regression and SPSS software for analysis. Results for 80 year – country show that there was a positive and significant correlation between GDP, export, import, inflation and insurance per capita, which shows whenever productivity increases, insurance increases too. Results also show that there was a positive relationship between import and insurance per capita. In addition, results show that there was a positive and significant relationship between inflation and dependent variable. However, there was no significant relationship between exports and insurance per capita. The results show that there was no significant relationship between GDP and insurance per capita and finally, there was a non-significant and negative relationship between private sector investment and insurance per capita.

Previous studies in the area of earnings forecasts hold a common characteristic, they make no distinction as to the economic cycle when evaluating voluntary earnings disclosures. This paper presents an empirical investigation to study the relationship between actual as well as forecasted earnings and growth domestic product during the economic growth and recession on Tehran Stock Exchange. Using the information of 60 firms over the period of 2007-2012, the study has determined that there was a positive and meaningful relationship between earnings forecast and growth domestic product during economic growth. In addition, the study has determined a meaningful relationship between actual earnings and growth domestic product during the recession.