如何定义远期价格函数?

How to define a function about forward price?

我必须定义一个函数,forward_price 它接受三个参数:

spot: float
interest_rate: float
time: float

此函数应使用以下经典公式计算并 return 远期合约中资产的远期价格,四舍五入到小数点后两位:

1

我试过了:

from math import e
interest_rate = 1.03 #risk free-rate is 3%
spot_price = 40 
time = 30/360 #there is 30 days remaining
forward_price = spot_price * e ** interest_rate * time 
print(forward_price)

结果是 9.336886115663596 而真实结果应该是 40.10

有人知道如何得到这个结果并四舍五入吗?

问题似乎出在利率加 1 上。如果您将 interest_rate 保留为 0.03 并在指数两边添加括号,您将获得预期值。

from math import e
interest_rate = 0.03 #risk free-rate is 3%
spot_price = 40 
time = 30/360 #there is 30 days remaining
forward_price = spot_price * e ** (interest_rate * time) 
print(forward_price)