After shaking up iron ore, steel and coal futures this year, Chinese investors have taken on copper. Bloomberg reports the metal jumped 11% last week, the most since 2011, as President-elect Donald Trump’s pledge to spend as much as $1 trillion on infrastructure boosted the outlook for demand. But the impetus for the surge probably had its origins elsewhere, namely in China. In the four trading days through Monday, copper prices on the London Metal Exchange peaked between 10:30 a.m. and 6 p.m. Shanghai time, and declined during London and New York hours. The daily volume for copper on the Shanghai Futures Exchange reached 1.83 million contracts on Nov. 14, the highest in almost a year, and was more than three times the open interest, suggesting short-term speculation, according to Marex Spectron Group.