单向双向：某些产品的手续费只在开仓时收取，有些则在开仓和平仓时都收取； The features that surface During this desk are from partnerships from which Investopedia receives compensation. This payment may perhaps impression how and the place listings look. Investopedia will not consist of all offers out there from the marketplace. 今日持仓/昨日持仓：中国期货通常指定平今仓和平昨仓来收取不同... https://pnl70133.theobloggers.com/40478279/a-simple-key-for-pnl-unveiled