The CSI 300 Index is a stock market index that tracks the performance of the top 300 companies listed on the Shanghai Stock Exchange and the Shenzhen Stock Exchange in China. It serves as a benchmark for investors to gauge the overall health of the Chinese equity market. Launched in 2005, the CSI 300 includes companies from various sectors, such as finance, technology, and consumer goods. It is widely used by fund managers and investors to make informed decisions and assess market trends in the rapidly growing Chinese economy.