NO.PZ2018091705000067
问题如下：
Explain two drawbacks to write covered calls as a monetization strategy.
选项： 解释：
There are two potential drawbacks with this strategy: The investor retains full downside exposure to the shares (to the extent the share price decreases by more than the premium received), and the upside potential is limited (the call strike price plus the premium received).
不明白最后一句，为什么最大收益是premium和strike price的和呢？
股价下跌时候，若太多，premium覆盖不过来，最多也就赚premium；
股价上涨时候，最多也就是strike price。
为什么就是两个的和呢？
