They do exist guys, and short SSF traders drive them sharply down early am,just to switch to long and ride the recovery wave back up. This sometimes happen within 30 mins,unnoticed by most normal market traders.. There is a strong correlation between the SSF close out margins being used up and the high/lows for the day/the SSF's price matrix.
If it's them, then the question should rather be HOW LONG can they carry on protecting the US market every time it crashes? Anybody who's done any kind of TA on the DOW will have (should have?) noticed the negative divergences over the past five years. The index increases artificially, when it should have dropped, or the drop isn't enough. Is this due to the actions of the PPT? And if it is, then surely the Fed's Reserves are going to dry up some time? Unless, of course, they make a truckload of money by getting rid of their stock when the prices are high again - hmm . . . that opens a beeeg barrel of worms . . .