We do not allow hedging for hedging, cross account or opposite hedging management, it takes place when you open long and short positions at the same time on Bright. Xin buys and sells between each other at a higher size, the margin will be 0.
As you open buy and sell positions for the same type of CFDs at the same size, you need only one margin, which you can see here.
When you work head level, the margin of CFDs is always 50%.