Jamie McDonald breaks down relative liquidity in commodity markets by explaining which commodities trade the highest volume and carry the biggest weighting in commodities indexes. Much like equities, commodities trade across a number of global exchanges. But, unlike a share in a company, a commodity contract is not fungible across exchanges. That’s why it’s important to think in terms of contracts and exchanges as well as individual commodities to determine relative importance in a global ecosystem. McDonald notes the dominance of energy commodities, particularly crude oil, and discusses the surprisingly high weighting of agricultural commodities despite their relatively low volume at the individual contract level. And he details how certain contracts on international exchanges, like those in China, can be useful indicators of global growth even if they aren’t considered benchmarks.