Can I trade exchange listed Nymex crack spreads on IB? If I create them using the combo trader it tells me that execution is not guaranteed, so I assume that means it's a software generated spread rather than an exchange one.
Nope! I've been asking about this for ages, but they just tell you to put it in the useless features poll. The "non-guaranteed" combo works, but the indicative quote is outside the exchange market so you're getting an inferior execution 95% of the time.