China’s securities regulator ordered the country’s major commodity futures exchanges this week to control speculative trading activity, sources told Reuters, after a surge in prices sparked fears of a boom-and-bust cycle. Commodity futures exchanges in Dalian, Shanghai and Zhengzhou ordered major institutional investors to rein in their trading. Investors, including hedge funds and retail investors, have placed big bets on Chinese commodities futures this year, driving up contracts including in iron ore, rebar, cotton and even eggs. The rally has prompted many analysts to warn of similarities with a boom in the country’s stock markets, which reversed into a sharp crash last summer.