Which Chinese stock-market index lost about 30% of its value in the summer of 2015?

The Shanghai Composite lost about 30% of its value in the summer of 2015.

China’s stock-market turbulence followed a powerful rally that had pushed share prices sharply higher. The Shanghai Composite reached a 2015 intraday peak on June 12, then fell rapidly; by early July, the decline from that peak was roughly 30%.

The sell-off involved leveraged retail trading, forced sales, concerns about economic growth, and official attempts to stabilize prices. Authorities restricted some initial public offerings, encouraged state-linked buying, and placed limits on selling by major shareholders.

The Shanghai Composite tracks companies listed on the Shanghai Stock Exchange, while the Shenzhen Component tracks a different exchange. The Hang Seng Index represents Hong Kong-listed shares, so these indexes should not be treated as interchangeable measures of Chinese markets.