问题如下：
A "buy-and-hold" investor purchases a fixed-rate bond at a discount and holds the security until it matures. Which of the following sources of return is least likely to contribute to the investor’s total return over the investment horizon, assuming all payments are made as scheduled?
选项：
A.Capital gain
B.Principal payment
C.Reinvestment of coupon payments
解释：
A is correct.
A capital gain is least likely to contribute to the investor’s total return. There is no capital gain (or loss) because the bond is held to maturity. The carrying value of the bond at maturity is par value, the same as the redemption amount. When a fixed-rate bond is held to its maturity, the investor receives the principal payment at maturity. This principal payment is a source of return for the investor. A fixed-rate bond pays periodic coupon payments, and the reinvestment of these coupon payments is a source of return for the investor. The investor’s total return is the redemption of principal at maturity and the sum of the reinvested coupons.
我可以理解持有至到期，capital gain是0，但是问题问total return，即总收益，那principal payment对total return的贡献又是什么呢？
