The days when manipulating the market was costing actual money are gone... With HFT algos they can jack the price up or down without net expenses. It's like using the zero-energy, the fluctuations of the void. You can create micro-momentum with a small expense to be recuperated immediatly in the outcome of the micro-momentum created. They wait for light limit order conditions and push through them, then they recoup the "investment" in the heavier limit order ladder created. Like this they can throw and catch immediately until the market is really exhausted, then they change the direction. It's really hopeless. Just a small change to the market rules could fix this. But with the corruption around, noone wants it...