China’s benchmark stock index dropped in volatile trading on the country’s last trading day this week amid speculation that state funds intervened to stabilize the market before a major military parade on Thursday. The Shanghai index has now crashed by roughly 40% from its June 12 peak, erasing all gains made this year.

China’s stock markets close for two days
China’s markets will be closed Thursday and Friday to commemorate the 70th anniversary of the end of World War II. Investors will now get a state-mandated break from the pain, as the China...

