问题如下:
A trader shorts 100 shares when the price is USD 50. The initial margin and maintenance margin are 150% and 125%. What is the initial margin required? How high can the share price go before further margin is required? (Ignore interest payments.)
解释:
The trader is initially required to contribute USD 2,500 in addition to the USD 5,000 obtained from selling the shares, creating a margin balance of USD 7,500. If the USD share price rises to X, the maintenance margin becomes 100 * 1.25X = 125X. This is greater than the 7,500 margin balance when X > 7,500/125, that is, when X > 60.
这题李老师课上也讲过,我还是不理解