What was the main stock index whose 8.5% fall on August 24, 2015, symbolized China's stock market crash?

The Shanghai Composite was the main stock index whose 8.5% fall on August 24, 2015, symbolized China’s stock market crash.

The index tracks shares listed on the Shanghai Stock Exchange and is widely used as a headline measure of mainland Chinese equities. On August 24, 2015, it suffered its largest one-day percentage decline in eight years, falling 8.49%. The date became known internationally as “Black Monday” for Chinese markets.

The crash followed a powerful rise that had begun in 2014. Concerns about slowing Chinese economic growth, excessive borrowing to buy shares, currency pressure, and government attempts to stabilize prices weakened confidence. Losses spread to markets elsewhere, contributing to a global equity sell-off.

The Shanghai Composite is not the same as the Shenzhen Component or Hong Kong’s Hang Seng Index. Those indexes represent different exchanges and sets of companies. Government interventions, including restrictions on selling and support measures, also made China’s 2015 turbulence different from a purely unrestricted market collapse.