Since the start of corona season, it seems that the U.S. has mostly followed what's going on with other exchanges, especially Europe's. But I've only been looking for about 3 months. What do the past 3 decades look like, generally speaking? Any thoughts?
sometimes it leads. sometimes it lags. sometimes it refuses to move. similarly for Asian (& Eur ) market. sometimes it leads. sometimes it lags. sometimes it refuses to move. so before you day trade, check past few minutes to past few hours of your charts.
What ever you expect it to do, trade the other way! Never trade the first 30-45mins, let them fight over which direction they want to take it. Used to be first 15mins but these days, they argue for longer.