What type of markets do 4% up days happen in?
I will give you a hint: it's not bull markets.
Huge up days are most likely reactions within bear markets. We had a s***oad of them in the move down from 2007 to 2009.
So as a bull, days like today (despite a nice bounce to kick the bears in the crotch for a few hours) are *not* what you want to see. Besides, the bears got wise and started wearing a cup.