The margin is increased at any time, just like the floating profit is constantly changing. For example, 3600 hands are empty, 1 hand 10 ton, and you lose ten dollars. If the margin is charged at 10%, 3600* 10 ton * 10% equals 3600 lots.

This ratio is a metaphor for knowledge.

As I said before, it is always recovered, and the deposit changes with the price.