Vulnerability of Contagion Network in Iran Stock Market: Complex Networks Theory Approach

In today's world, the interconnected structures of modern economies have caused the crisis to spread from one sector or country to other countries or sectors of the economy. Empirical evidence has shown that markets are interconnected and do not move apart. In the present study, a new approach is presented to investigate the contagion effect in Iran stock market. First, with the economic analysis, a network of 36 selected industries of Iran's economy is formed in accordance with the industries active in the stock market and the weight of the edges that connect them is determined according to the input- output table of Iran. In the next step, a correlation network is formed between the stock market indices of these 36 industries by using centrality criteria, Key industries are identified and then attacked. Comparison of the results of the two networks show that only in a limited number of cases in both networks, the basic metals industry, the banking industry, investment and other financial intermediaries, and the agricultural industry have won first place in accordance with a number of centrality criteria. But in other cases, the two networks have not the same results, which shows that economic relations among industries do not dominate their stock market index relations alone. The results of this study help both policymakers and shareholders to make appropriate decisions as soon as they see a crisis in important industries of the stock market.