This amounts to a big drain on a buyer's compounded returns.

这相当于对买家的复合回报造成了很大的损失。

A very simple scheme ensured that, come what may, his private clients received compound average annual returns of a steady 15% on their investments.

他制定了一个非常简单的方案，无论发生什么，都要保证私人客户获得稳定的15%的平均年复率回报。