Depends on the day, but I'd say, on average, the NQ is first, then YM, then ES. Sometimes, though, the YM leads the NQ. The ES usually seems to be in last place.
But it's certainly not a foolproof design. Sometimes I'll see NQ take off in one direction or the other and will jump on an ES trade only to be smashed to pieces when the NQ, just as quickly, reverses.
