I am happy to discuss these issues, but would rather have a fact based discussion than resort to insults. Firstly, not sure what you think the distinction is b

I am happy to discuss these issues, but would rather have a fact based discussion than resort to insults. Firstly, not sure what you think the distinction is between HFTs as opposed and "algorithimic market makers". I think most people would equate them, for instance most would agree that firms like Virtu Financial and Knight Capital Group are both HFT firms and market makers (for instance, they are Designated Market Makers on many NYSE securities, the closest thing we have to an "official" market maker these days). Second, HFTs definitely make more money in moderate to high vol (the current period of prolonged low vol in the markets has been pretty hard for the sector), and during those periods it seems even you agree that they are providing liquidity - and I would argue, adding value. During extreme vol events, yes HFTs will pull out of the market, but so does everybody else. If they can manage it, they will liquidate positions, but their books are small relative to other players, I am skeptical that this is an important factor in further increasing vol, will stand corrected if you can point to me evidence it is. If HFT is really making vol worse, then why are we not seeing higher vol since it became prevalent? Certainly, we have had periods of great macro uncertainty in the last half a dozen years, but there was no apocalypse in the market. Finally, my point in bringing up the NASDAQ broker example, is that HFTs perform an important function as market makers. If you want to get rid of HFT and do not propose who's going to take their place, I have to assume we would go back to the old system of human market makers. I think pointing out their flaws is entirely fair. It's easy to demonize HFTs, but nobody forces you to trade with them. It would be relatively easy to setup a darkpool that does not allow HFTs to trade there. Some people have tried this (or at least to market the notion that they tried), but inevitably they decide they need HFT liquidity and end up courting them instead.