The Hang Seng Index is a selection of companies from the Stock Exchange of Hong Kong. They are a free-float capitalization-weighted index. The index is divided into four components which are known as subindexes. They are Commerce and Industry, Finance, Utilities and Properties.
The Hang Seng Index, also known as HSI, opened on November 24, 1969. It is now managed and maintained by HSI Services Limited. This is solely and wholly the subsidiary of Hang Seng Bank which is the largest bank in terms of capitalization that is registered and listed in Hong Kong. It compiles, publishes and manages the Hang Seng Index in addition to other stock indexes such as Hang Send China AH Index Series, Hang Seng China Enterprises Index, Hang Seng China H-Financials Index, Hang Seng Composite Index Series, Hang Seng Freefloat Index Series and Hang Seng Total Return Index Series.
This index is used to monitor and record the daily changes that occur with the largest companies that are a part of the Hong Kong stock market. It is used as the barometer for the overall market performance in Hong Kong. There are 45 companies that are part of the index and these 45 companies make up 67% of the capitalization of the Hong Kong Stock Exchange.
The Hang Seng Index uses a unique classification system called the Hang Seng Industry Classification System. It is a special system that is designed specifically for the Hong Kong stock market and reflects stock performance from different areas.