For investors trying to decide which commodity and/or mining company to get exposure to, UBS is the latest broker to pick copper over iron ore and lithium amid signs of dwindling supply for the base metal.

Copper on the London Metal Exchange is trading near the highest level in almost four weeks of around $US9944 ($14,748) a tonne after rallying almost 4 per cent in the last week. That’s after rocketing above $US11,000 earlier in the year as traders ramped up bets that producers will struggle to meet growing demand for the industrial metal.