Industrial metals index

What it is

An index made by the World Bank that combines world prices of aluminium, copper, iron ore, lead, nickel, tin and zinc, weighted by how much of each is traded. These are the metals that go into buildings, cars, wiring, batteries and machines.

The units

An index, not a price: 2010 = 100. A value of 120 means these metals cost on average 20% more than in 2010, in US dollars and before adjusting for inflation.

What moves the price

Building and factory activity, especially in China, which uses about half of the world's industrial metals; mine supply and strikes; energy costs (making aluminium uses a lot of electricity); and new demand from electric cars, power grids and solar panels.

Why it matters for everyday prices

Metal prices end up in the cost of cars, appliances, houses and electronics. Because they track factories and construction, people watch them as an early sign of how the world economy is doing.

Prices of single metals are set on the London Metal Exchange and other exchanges, which license them, so we show the World Bank's index instead.

Where the numbers come from