The price paid up front is the present value of all the future cashflows of coupons and principal on maturity, discounted at the appropriate interest rate, which is also known as the yield to maturity (YTM) of the bond.

• 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”。