Copper Tumbles Most in 6 Years Amid Commodity Collapse

Copper tumbled the most in almost six years to below $5,400 a metric ton as speculation that demand for raw materials won’t be enough to eliminate a supply glut triggered a sell-off in industrial metals.

Copper slumped as much as 8.7 percent in London and fell to the daily trading limit inShanghai. The world economy will expand 3 percent in 2015, according to a World Bank report, down from a…