NO.PZ2023052301000041
问题如下：
An investor purchases an eight-year, 6.4% annual coupon eurobond priced at par and sells it after six years. Assuming interest rates rise by 100 bps immediately after purchase, the investor’s rate of return at the end of six years is:
选项：
A.
lower than 6.4%.
B.
equal to 6.4%.
C.
higher than 6.4%.
解释：
A is correct. The future value of reinvested coupon interest is
= FV(0.074,6,6.4,0,0) = 46.245.
The sale price of the bond at the end of six years is
= PV(0.074,2,6.40,100,0) = 98.202,
which results in a six-year horizon yield of 6.32%, which is lower than 6.40%:
B and C are incorrect, because interest rates have risen and the investor’s investment horizon is not long enough to offset the price decline with additional reinvestment return.
八年，Ri影响是6年，price影响是2年。从简单的思路来说，再投资收益的影响肯定更大吧，那实际收到的回报应该更大吧？
相同的思路，我看了基础班讲义的218页的例题，那一题是五年期的债券，第二年卖掉，利率也是在他买入后马上上升的。我理解为，再投资收益影响两年，price影响三年，Price影响更大再投资影响更小。所以那题没有实际计算，就可以推出来return是比coupon小。
所以疑惑课后题的思路为什么在本题不适用呢？