Its illusory. Let's say you are trying to buy 500 shares of stock and HFTs are showing 100/100. You attempt to buy 500 shares at the offer. Either you don't get filled at all, or you get filled for 100 shares and the HFTs readjust 10 or 20 cents upwards. I've been trading for a long time. I'm just saying that it used to be where you could do some fairly decent size on illiquid securities if you were willing to give up the spread. Now you can't do that. Anybody who claims HFTs are good for the market (and let me be specific: in terms of the retail trader) is just a shill for the HFT industry. I would much rather have the antiquated specialist system in place, rather than this crapfest we have right now.