I tried asking this in IB live chat awhile ago but did not get a clear cut answer. Also tried emailing management but no answer back yet. My question is, why won't IB recognise a 1:1 spread between the e-mini SP and e-mini Nasdaq? The CME span margin for this spread is $3,750 as opposed to $11,063 ($4,313 ES + 6,750 NQ) I am currently margined. Thanks.