The $USD

To go along with my earlier Guess, take a look at the $USD which has an inverse relationship to stocks and most commodities (they move opposite each other).

 This short term 2 min chart move up in the $USD is what is helping send market prices down, it's too parabolic and it has a short term negative divergence, I don't think this will hold, if this falls, then the market should see the knee jerk strength I mentioned.

 Go to the 15 min chart though and the $USD has a very strong positive divergence

 The 30 min above and 60 below also have very strong leading positives, this would represent the move down in the market as the $USD moves up.

It fits almost perfectly with what I posted earlier.