I'm still having trouble getting up the box structure such that I can trade it as a combo rather than legging in. I believe since this is showing as Non-Guaranteed that means I'm legging in, right?
Do a search here for IB and "The Algorithm". They have a habit of autoliqudating things like vertical spreads that couldn't possibly lose more money then used to purchase them or the width of the spread because "The Algorithm" isn't programmed properly, among other things. And their "customer service" is both too stupid to grasp the issue and too indifferent to care. Truly one of the worst companies I've ever worked with.
Because @Sig says so and doesn't like IB. He had bad experiences with IB in the past and thus presumes that all IB's customers have (or will have) bad experiences.
Your fear is unjustified. You use a combo (because you selected combo in TWS) so what do you think the market sees......? (It's just a generic warning not applicable for your situation)
For the answer you should read this link (and the comments): https://www.elitetrader.com/et/thre...n-ibs-margin-rates.341064/page-4#post-5030330 Quote: Box spreads don't allow levering up. They just reduce your interest rate plain and simple.
Do a search for "autoliquidation" and you'll find literally dozens of threads, all related to IB oddly enough, from dozens of people who have experienced the same thing. IB depends on "The Algorithm" to do auto liquidations and "The Algorithm" doesn't properly calculate the max possible loss on vertical options spreads. Everyone is subject to the same code, and if you haven't been impacted than you either don't trade them or haven't been in a situation of wide bid/ask spreads being incorrectly interpreted as larger than possible losses by "The Algorithm". This thread involves spreads that would be subject to this known error. Those are all simple facts, there's no "presumption" going on. If you trade straight stocks without margin, IB is great for you. Carry on, and don't feel the need to comment on threads that involve vertical spreads at IB. If you engage in anything that involves a vertical spread, and the topic of this conversation does, then there's a known issue at IB with that. I'm not sure why you're attempting to color that as just some kind of bitterness on my part, presumably to be ignored for that reason? Do you dispute any of the above?