They look alike on surface, but....

You can see that from 2/21 to 3/3, SPX is pretty much going down in an impulsive wave and cut through 50D MA like a hot knife. 

So far, SPX is grinding, and as long as it is grinding, it is an encouraging sign. But if you see a sudden dive like the ones you see from 2/24 to 3/3, then a large correction is likely on the way.