To be fair "researchers" have also stated the converse: http://people.stern.nyu.edu/jhasbrou/Research/Working%20Pape... http://www.automatedtrader.net/headlines/127545/hft-helps-ma... http://home.uchicago.edu/~bweller/files/Liquidity_and_High_F...

Not sure what we're arguing about. I never said HFT is "justified" by its infusion of liquidity. It is simply a function of High Frequency trading, whether justified or not.