I wasn't aware of this. What kind of collateralization ratio is required and what sort of assets are needed for this? Also signing up for an account from many countries sounds irritating and possibly illegal
Collateral requirements vary by asset and account country according to national law. Generally it’s 50% LTV on equity collateral but leverage can be higher depending on the case.
I paid for a house with their margin to avoid triggering gains on long term positions, while waiting for some locked up options to liquidate.