The Shanghai Composite Index lost 6.42% on 19 June 2015 during China’s stock-market crash.
The fall was the index’s largest one-day decline in several years at that point and helped mark the beginning of a steep reversal after an extraordinary rally. Chinese mainland shares had risen rapidly in the preceding months, encouraged by margin borrowing, new-account openings and widespread retail speculation. Valuations and leverage then became major concerns.
The Shanghai Composite continued falling through the summer, with another major sell-off on 27 July and the global “Black Monday” market turmoil on 24 August. Chinese authorities responded with measures including trading suspensions, restrictions on some sales and support intended to stabilize prices. The 2015 episode is often confused with the separate 2015–16 turbulence, which describes the broader period rather than one single trading day.