If hedging is not the norm in a certain industry, it may not make sense for one particular company to choose to be different from all others. A company that does hedge can expect its profit margins to fluctuate!

我就不明白了，如果购买futures进行hedge,应该能保证profit,规避风险，怎么这里的profit margins 反而会fluctuate? 边际利润波动是怎么得出这样的结论的？