spread betting
noun/ˈspred betɪŋ/
/ˈspred betɪŋ/
[uncountable]- a type of betting in which you bet money on whether you think the predicted outcome is too high or too low. The amount of money you win or lose depends on the extent to which you are right or wrong.
指数博彩，差额投注（判断预测的结果过高还是过低的博彩，输赢金额依判断的准确度而定）