This is what professionals call a WTH market (the "H" stands for heck).
Markets undergoing vast changes in their technical outlook on a minute to minute basis are best described as WTH markets. I have no doubt that investors who have been trained, and thus far rewarded, to "buy the dip" were putting money to work early this morning as the S&P 500 screamed higher, but I also have no doubt they are now remorseful buyers.
The market looked equally as horrible on the close as it looked fantastic on the open. In such markets, typical market analysis techniques simply don't work and traders attempting to chase prices back and forth will wish they had never heard of momentum indicators.
In the past, WTH markets have been followed by big moves so traders should approach the S&P with more caution than usual.