这笔钱就是投资者将来会收到的利息和到期时会取回的本金的现值，而所用的贴现利率就叫做“到期利率”。

• The price paid upfront is the present value of all the future cash-flows of coupons and principal on matu-rity,discounted at the appropriate interest rate,which is also known as the yield to maturity (YTM) of the bond.