The interesting thing is that the premium yesterdey for ES/SPX was 4.5 points and YM?DJX 30 (which is 3 ES points).
Can be some kind of strategy worked out to take advantage of this? (because they tend to move together)
Also today the ES/SPX premium collapsed and it was down to 3 ES points, thus there was no longer difference between the two.
So I guess with some kind of arbitation a 1.5 or so points could have been made...