Which index fell 8.5% on the first trading day after the 2015 Chinese stock-market crash began?

The Shanghai Composite fell 8.5% on the first trading day after the 2015 Chinese stock-market crash began.

On June 15, 2015, the Shanghai Composite dropped 2.2%, beginning a turbulent period after the index had more than doubled over the previous year. The sharpest early fall came on June 26, when the index lost 7.4%, followed by a 8.5% decline on July 27. The 8.5% figure is therefore associated with the first trading day of a major renewed sell-off, not the first day of the entire episode.

The turbulence was linked to heavy margin borrowing, high valuations, slowing economic growth, and official efforts to cool excessive speculation. Authorities responded with measures including trading restrictions, investigations, and support for share purchases.

The Shanghai Composite tracks many companies listed in Shanghai. The Shenzhen Component and Hong Kong’s Hang Seng Index are separate benchmarks, so they should not be substituted even though all were affected by regional market stress.