Which index became the main measure of China's 2015 stock-market crash?

The Shanghai Composite became the main measure of China’s 2015 stock-market crash.

The Shanghai Composite Index rose rapidly during the first half of 2015, helped by margin borrowing, strong retail participation, and optimistic expectations about Chinese growth. It reached a closing peak of 5,178.19 on June 12, 2015. The index then fell sharply, losing roughly 43% by its late-August low.

Chinese authorities responded with measures including interest-rate cuts, trading restrictions, state-linked purchases, and investigations into market activity. The turbulence also affected global markets because investors feared that China’s slowdown would reduce demand for commodities and manufactured goods.

The Shanghai Composite tracks shares listed on the Shanghai Stock Exchange, including both companies incorporated in mainland China and other eligible securities. It is not the same as the Shenzhen Component, the CSI 300, or Hong Kong’s Hang Seng Index, though all are widely watched indicators of Chinese or regional markets.