虽然煤炭期货这种新事物所具有的潜力将改变美国煤炭工业的主要方面，但在很多情况下又很有争议。比如尽管实际上它的主要作用之一是为了降低风险，但却常被人们认为具有风险，所以行事谨慎的人都力争避开它。无论如何，煤炭期货的出现将使煤炭交易增添动态的特征。虽然它最终 While the potential of such new things as coal futures will change the major aspects of the U.S. coal industry, it is in many cases controversial. For example, despite the fact that one of its main functions is to reduce the risk, it is often regarded as risky, so those who exercise caution try to avoid it. In any case, the emergence of coal futures will add dynamic features to coal trading. Although it eventually