NO.PZ2020021203000061
问题如下：
Give two reasons why it is not optimal to exercise anAmerican call option on a non-dividend-paying stock before maturity. One reason should involve the time value of money. The other should involve the loss of optionality.
解释：
Delaying paying the strike price allows interest to be earned on the strike price for a longer time period. The call option also provides insurance against the event that the stock price becomes less than the strike price at maturity. Once the option has been exercised, this optionality will be lost.
time value只是拿着买股票的X折现再投资？不包括那个time value？就是等待是有意义的，时间越长T有赚更多的可能性？
