问题如下：
XYZ company has issued a 4-year semi-annual bond with a coupon rate of 8%, the bond's current price is 105, what`s the bond's annual yield-to-maturity?
选项：
A. 3.27%
B. 6.56%
C. 5.33%
解释：
B is correct.
PV= -105, N= 8,PMT= 4,FV= 100, CPT → I/Y= 3.2703
r=3.2703% is not annualized YTM, so annualized YTM=3.2703% × 2=6.5586%
想问一下这道题的计算器使用，如果我按N=8，PV=105, PMT=4, FV=-100算出来怎么收益率为负？所以计算器使用的时候讲的同时输入FV和PV一个为负就可以这个结论是不对的是吗？像这样的情况应该怎么判断啊