NO.PZ2018053101000036
问题如下：
Which of the following statements about commodity investing is invalid?
选项：
A.Fewer commodity investors trade actual physical commodities. B.Commodity producers and consumers both hedge and speculate. C.Commodity indexes are based on the price of physical commodities.解释：
C is correct. Commodity indexes typically use the price of futures contracts on the commodities included in them rather than the prices of the physical commodities themselves in order to be transparent, investable, and replicable.
A is incorrect because trading in physical commodities is primarily limited to a smaller group of entities that are part of the physical supply chain. Thus, most commodity investors do not trade actual physical commodities but, rather, trade commodity derivatives.
B is incorrect because although supply chain participants use futures to hedge their forward purchases and sales of the physical commodities, those commodity producers and consumers nonetheless both hedge and speculate on commodity prices.
B选项，我觉得speculater不太可能会是大宗商品的producer和consumer吧，他们不是只是赚差价么
