这句话怎么理解American call option holder can exercise early to capture the value of the dividend.

问题如下：

Which of the following circumstances will most likely affect the value of an American call option relative to a European call option?

选项：

A.

Dividends are declared

B.

Expiration date occurs

C.

The risk-free rate changes

解释：

A is correct.

When a dividend is declared, an American call option will have a higher value than a European call option because an American call option holder can exercise early to capture the value of the dividend. At expiration, both types of call options are worth the greater of zero and the exercise value. A change in the risk-free rate does not affect the relative values of American and European call options.

中文解析：

首先美式期权可以提前行权，欧式期权不可以提前行权。

那什么时候美式看涨会提前行权呢？

就是当未来dividend足够大的时候。因为发放股利会使得股票的价格下降，当股利足够大的时候，大到超过了time value(因为不提前行权，期权有时间价值， 提前行权相当于放弃了时间价值），美式看涨期权就会提前行权。

如果未来没有div，美式看涨期权不会提前行权，此时美式跟欧式就一样了。所以股利对美式看涨的影响更大。

B选项：在到期日的时候，美式和欧式看涨的价值都一样，没有差别。

C选项：欧式和美式期权都会受到无风险利率的影响，不选。