Raw materials: Physical silver in short supply

Trump causes copper rally

The price of copper has been extremely volatile in recent weeks. "US President Trump's announcement of a 50 percent import tariff on copper triggered a sharp rise in the industrial metal traded on the US commodity exchange CME COMEX," said Tahir. The sharp price divergence on COMEX and LME, he believes, indicates "that the markets are still adjusting to the new reality."

WisdomTree Copper ( GB00B15KXQ89 ) also benefited from the increase, becoming the most-traded copper ETC on Xetra in June. At Vontobel, the Long Mini-Future on copper ( DE000VP3KBF5 ) is currently one of the three most-traded products. "The breakdown of trading positions into long and short products shows that investors view copper very positively," explains Hartmann.