That's because nobody trusted these banks they could go under any day and so they tended to sell at a discount.

那是因为没有人信任这些银行,它们可能在任何一天倒闭,所以它们倾向折价卖纸币。

耶鲁公开课 - 金融市场课程节选

So you buy it at a discount and the return you get is of course a hundred minus--the return you get is the discount.

所以以折价买入,并且回报等于,100减去,回报等于折扣差价

耶鲁公开课 - 金融市场课程节选