I use IB as second backup broker for various reasons, cheap commissions is seldom ever cheap as they have gotten so enormous through the years, they have no wiggle room like a smaller broker does wanting to keep you as a customer, IB doesn't care whether you there or not. The answer is simple, liquate holdings and make them happy, they have enough legal to make you know you did wrong. Should have lighten the load Friday before or taken insurance to offset risk, but you rolled the dice? You already knew about IB beforehand, so you really have no complaints. Am sure if they owed you, would you agree to payment plan?