HONG KONG -- The Shanghai Composite Index on Tuesday temporarily exceeded 4,000 for the first time since July 2015, but traders and regulators have not forgotten the plunges that have historically followed such gains.
Previous stock price surges have been followed by sharp drops and volatility

The Shanghai Stock Exchange Composite Index temporarily surpassed 4,000 on Oct. 28 -- its highest in just over 10 years. (Photo by Noriyuki Doi)
HONG KONG -- The Shanghai Composite Index on Tuesday temporarily exceeded 4,000 for the first time since July 2015, but traders and regulators have not forgotten the plunges that have historically followed such gains.