Feds are the plunge protection Team. The Treasury Depart is the plunge protection team US congress and Senate banking committee are the plunge protection team Fighting them is like picking a fight with US army and US Air force on a battlefield. There are numerous other big trading houses working in concert with Feds and Treasury so our financial markets cannot be hijacked by terrorist or rogue nations like North Korea or Iran or Hugo Chavez or Cuba and hand a total collapse of US economic system and financial markets. That why you see SPX comes down and stops on a dime, as if struck by a whip. Imagine this: A rogue sell program originating in Tehran starts overnight burying S&P futures and sinks US economy Monday morning?
There is no such " free markets " in the US. Are there any free Casinos in Las Vegas where you can upset the house? We are heavily regulated and monitored and controlled. The Feds stand over them like armed guards at Fort Knox. You are just allowed to put your bets and get out