Industrial metals from copper to aluminum to iron ore have rallied to the highest level in years.
The reasons for their gains are plentiful: Copper -- critical for everything from electrical wiring to motors and thus a bellwether for the global economy -- broke out of its recent range to trade near the highest since the last supercycle as industrial operations ramp up worldwide. Iron ore, aluminum and steel are meanwhile gaining on speculation that production cuts will shrink supplies just as demand is taking off. And a weaker dollar is making commodities traded in the currency cheaper to buy.
