Trend: Demand for metals outstrips supply.
Copper has soared 180% since June 2003, far more than gold's 48% rally or silver's 91% gain. Even crude oil has only doubled.
What's behind this explosion?
"Old-fashioned expansion," said William O'Neill, a partner at Logic Advisors LLC, a commodity consulting company in Upper Saddle River, N.J. "Emerging powers are continuing to grow their demand, and supply just can't keep up."
Unlike precious metals, which attract lots of speculative buying amid fears of what might happen, copper is flying on what is happening. "This (copper) is not an inflation story," O'Neill said.
Copper is a core industrial metal, used extensively in autos, construction, wiring and other fields. Its price rises and falls with the global economy, which is enjoying its best boom in 30 years.