Who knows how much HFT is going on in the U.S. but I know the Australian market is pretty much completely infested with it and it is ruining a lot of companies by supressing the SP so much that a lot of investors I know have pulled out of the market because of them.
Its not just the HFT's in Aust but insider trading and info being passed around between those people that have an inside line on companies. With what was a useless regulator now being stripped of its funding by the Government it will be completely open season once the new budget is passed. Any company small to medium sized will have its SP completely manipulated by HFT.
Just my opinion but based on years of being in the market.
