I am considering moving to IB with a portfolio margin account. I understand that in the past there was a problem with the automatic liquidation algorithm of IB, where some of the legs of Euro style credit boxes on an index (SPX for instance) could be automatically closed for risk management. Apparently the reason for this is that the algorithm prices the box according to the bid-ask spread (which could be a problem with illiquid contracts), as opposed to just setting the margin requirement to the difference between the strikes. I have searched this and other forums to check if the problem has been fixed, but I haven't found any answer. Any input would be appreciated, I'm really liking IB for many reasons, but this issue would prevent me from using it.
Portfolio margin traders can suffer margin calls if they have a bad mark/quote. This is a huge problem at Interactive Brokers. TD Ameritrade seems to be a lot smarter about this. You need to place a GTC close order at a very favorable unrealistic price to always quote your box.
Thanks for the info! Good to know that the placeholder GTC order works, it's an extra step but easily doable. TDA is nice as well but it is lacking features and products that I'd need.