Yes, that is clear that they step in. But it says that IB would speak to their customers then. But if IB actually messed up with the initial margin and the system freeze, then I would say that IB has to reverse the trades and return every cent to their customer. Not just assume the extra loss...
What happens if IB did not take the required initial margin and actually let the customer overtrade? Initial margin $8k for ten contracts would be €80k margin requirement. Because it seems that the system of IB assume dthat 0 would be the bottom and applied a margin of nil to the contracts that...