okay, I got a little breather while price is chopping. what I mean by it depends is, right now the YM is up 70 and the ES is up 14 points. There's an imbalance there.
But the thing is, the Dow is loaded with heavy hitters, it's a quality index, so you can't just say the YM is going to snap up another 70 pts to match the ES. But the ES is a much thicker index (500 companies) and is much more heavily traded, so you can't just say that the ES is going to come down to meet the YM (like how some people use the EuroStoxx 500 to scalp the DAX because the DAX normally overreacts and snaps back to the Eurostoxx index).
The Dow is too high quality to always snap back like that. Does that make sense?
The balance between the two gives you good information, but it's just information, just another tool.
If you were looking for a lower quality index to match up against the ES, the NQ generally ah sdiht. Gotta go tradE!