NO.PZ2020020601000007
问题如下：
In the futures market, how is the margin account between a retail trader and his/her broker managed differently from that between a CCP member and the CCP?
选项：
解释：
In the case of a retail trader, there is an initial margin and a maintenance margin. The margin account balance is adjusted each day to reflect gains and losses. If the balance in the margin account falls below the maintenance margin level, the trader is asked for funds to bring the balance up to the initial margin level. For the member of an exchange, the maintenance margin and the initial margin are effectively the same.
记得上课学的都是，一开始交初始保证金，然后设置一个维持保证金，低于这个保证金的时候打电话补钱补到初始保证金。
CCPmember和CCP之间这个为啥是一样的，那岂不是补钱的频率会很高
