The Hang Seng Index is a stock market index that tracks the performance of the largest and most liquid companies listed on the Hong Kong Stock Exchange. It serves as a key indicator of the overall health of the Hong Kong stock market and the economy. The index includes 50 major companies, representing various sectors such as finance, technology, and consumer goods. Established in 1969, the Hang Seng Index is calculated using a free-float market capitalization methodology, which means it considers only the shares available for trading. Investors and analysts often use this index to gauge market trends and make informed investment decisions related to Hong Kong and the broader Asian market.