Margin is the USDT which makes up at maximum 10% of the GOLD value. (Total USDT - Buffer = Margin)

The maximum which can be skimmed is all of your margin (extremely unlikely, <0.0001% chance).

The most common case, and average skim, will be 10% of your margin.

With an example:

I hold $1,000 of GOLD, and staked 200 USDT.

Therefore, my margin is 10% of my $1,000 in GOLD, which is 100 USDT.

On average, and the most common case, is that I will be skimmed around 10 USDT. However, in an extremely unlikely scenario, the maximum upper bound is that I can be skimmed for 100 USDT.