The ratio was calculated based on the market capitalization of 287 companies. With a 6.5 quadrillion rial ($17.2 billion) market cap, TSE’s 29 chemical producers were at the top, followed by base metals group and banks and credit institutions, Securities and Exchange News Agency reported. The P/E ratio is use to assess a company’s value by measuring its current share price relative to its per-share earnings. It can be calculated as market value per share divided by earnings per share, according to Financial Tribune.