Quote from GTS:
Let's be clear here - performance bond or not, it would be quite easy for a highly leveraged IB IRA to go negative with futures - the market just has to gap widely against your futures position and you would be negative before they could liquidate you.
Presumably IB would require you to bring the account to zero but IRA rules might prevent you from doing that lest you create a situation where you have over-funded your IRA...not sure what happens in that case....I wonder if IB would let you square the account by making a cash transfer from a non-IRA account.
Disclaimer: I do have a IB SEP-IRA account that I trade futures in but I keep plenty of extra cash/equities in it.
They cannot require you to make up any loss. The trustee is the owner of the account and you are just the beneficiary.
They do not and cannot legally require that you guarantee the account personally.
They would just have to take the loss themselves. Presumably they believe that their margin requirements and monitoring are good enough to stop any loss from getting out of hand.