There is lot a correlation between indexes.
If Dow Jones Index moves, in most case SP500 and NASDAQ will also move in the same direction.
Let say, you buy ER2 (Russell2000 Future) when he break its resistance.
Do you think it’s necessary to pay attention to other indexes like YM, ES or NQ and look if they break their resistance too to confirm your trade?
You can do that, but you will probably miss a lot of moves.
I think that when trading ER2, you should not look at any other index because ER2 is the leading index.
ER2 moves often ahead of YM, ES or NQ.
When others indexes are moving upwards and ER2 go in the opposite direction, it’s generally a sign of market weakness.
I read a study about that, but I have to look at my bookmarks to give you the link.
I will probably make another post just for this study.