I am trying to figure out why Fidelity has to insist on enforcing good-faith rules in my 401k account. I have an IB IRA "margin" account and they don't care. (It's not a true margin account since I can't borrow but trades settle immediately). I am thinking about moving my account from Fidelity somewhere else but I already have too much money at IB and don't want to put all my eggs in one basket (MF Global comes to mind). What other brokerages allow "margin" IRA accounts?