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?
Thinkorswim offers limited margin accounts... https://www.thinkorswim.com/tos/displayFaq.tos?categoryKey=...IRA+basics