Hang Seng Index or HSI for short, is an equity index comprised of 50 of Hong Kong Stock Market’s largest companies. It is commonly used to measure the performance of the Hong Kong stock market, as these 50 companies make up approximately 58% of the market’s total capitalization. Hang Seng consists of sub-indices that break up companies into sectors in order to make tracking simpler. These sub-indices include: finance, utilities, real estate, and industry. Companies that are part of the Hang Seng Index include Lenovo, Tencent, HSBC, and Bank of East Asia.