Whenever you are trading with CFDs (Contracts for Difference) and you wish to open and maintain a position with a given instrument, there will be a required margin of funds (collateral/blocked funds).
The required margin is only a part of the whole position’s value due to the use of leverage on CFD. However, the profit or loss that the position generates is calculated according to the whole held quantity according to the magnifying leverage.
The margin of a position is a dynamic value. When you open a position, its margin is calculated and updated live according to the current price responsible for the closure of the position - that is the Sell price for Long positions and the Buy price for Short positions.
The funds will be blocked while the position remains open and will be released back to your free funds once the position is closed.
For Example:
If you are to open a position with 100 CFD units of Gold with leverage of 1:20 at the current price of $1,728.10, the margin for opening the position will be $8640.5. These funds will appear blocked until the position is closed.