问题如下:
Use a two-step tree to value an eight-month American put option on a futures contract. The current futures price is 58 and the risk-free rate is 5%. The strike price is 60 and the volatility is 24% per annum.
选项:
解释:
The option is exercised at node A. The value today is 5.478.
u=e^24%*(8/(2*12))^(1/2)=1.1486
d=0.8706
pu=(e^(5%*(8/(2*12))^(1/2)-d)/(u-d)=57.08%
pd=1-pu=42.91%
那第一步的payoff不是2*42.91%/(e^(5%*(8/(2*12))=0.8338吗