China’s developers are swinging wildly after world-beating gains this year. Ten-day volatility for a Bloomberg Intelligence index of 22 property companies surged on Wednesday to the highest since July 2015, as developers rallied after a bloodbath on Monday and additional declines the following day. By Thursday, most were falling again. Trading has turned wilder for Chinese developers after new property curbs clouded the outlook for earnings, which have been soaring for the industry’s biggest players. Investors are also weighing the debt burdens of companies such as Sunac China Holdings, which splashed out on acquisitions including the purchase of Dalian Wanda theme parks. On Thursday, Sunac led declines among the index members, slipping as much as 4.9% in Hong Kong. It’s up 424% this year, one of the world’s best performers among big companies. Kaisa Group Holdings’ price swings are among the most extreme for Hong Kong-traded stocks, using a 20-day measure.