Some commodities have now wiped out all of their 2021 rally: Here's why

For all the talk of a commodities boom, some markets have now wiped out gains for the year and several more are close to doing so.

Soybean futures have erased their 2021 advance, sliding more than 20% from an eight-year high reached in May, while corn and wheat have also tumbled. The Bloomberg Grains Spot Subindex slid the most since 2009 on Thursday, before edging higher on Friday as markets recovered some losses. Other commodities that have seen their big rallies evaporate include platinum, while once-surging nickel, sugar and even lumber have faltered.

The fact that some markets are falling while others