Customer equity is $20.6 billion according to http://www.interactivebrokers.com/download/2010-11-Monthly-Brokerage-Data.xls. CFTC numbers are misleading because they show only part of equity involved in futures trading. IB does everything possible to minimize it to protect customers (see another active thread about SIPC protection).
If you are spread trading, make sure that the FCM risk manager has set up your account correctly for the intra and intercommodity SPAN margin credits - it makes a little bit of capital go a long, long way and you can carry them days and weeks with the correct margin offsets. For example, you can carry a tier 1 or 2 Eurodollar calendar spread for less than $600. And then leverage the piss out of it if you'd like.
Can only imaging the flaming someone like Surf would absorb for a suggestion like that... In any case, thanks to everyone for the good color and insights.
Well, the ability to leverage a futures spread is not my opinion - just fact. Look at the performance bond margin credits you get for inter and intra-commodity spreads in each exchange's margin rates which are posted on their websites. If you can select a spread whose price action is smoother and more predictable than a flat price market... and then the exchange bends over backwards to encourage you to trade them from a capitalization efficiency standpoint... IMO it is a very big advantage and a road a little less travelled.
Advantage has a difficult time defining their margins for interest rate spreads. Man Fin does a much better job, imo/ime
I actually clear them both, no problems for me. But as I mentioned in a previous post, you do have to make sure your FCM's Risk Manager is on board and can enable your execution platform to recognize the overnight SPAN margin credit offsets on an intraday basis. It is also somewhat sensitive to the front-end you are using - I know for a fact that Pats is terrible to work with from an intraday spread margining standpoint. TT and CTS appear to be rather simple to set for it. If you let Terry Duffy over at Advantage know what you are doing, he will make sure that Risk makes the required adjustments to your account settings. Both Man and Advantage (and RCG, RJ O'Brien, Cunningham, etc. etc.) clear many large spread traders - individuals, prop, institutions. The big piece is that the margin offsets are not automatic on an intraday basis - you have to make sure that your FCM has made the correct allowances. I have also seen it where the FCM does not give you enough of a margin offset allowance. For more retail-oriented FCMs it is a huge issue, because all of their clients are trading futures flat price directionally with outright risk and they typically don't want to be bothered.