Yes. You get liquidity, meaning more investment is available for some companies - people who would have not invested now will invest. The spread is lower, ben

Yes. You get liquidity, meaning more investment is available for some companies - people who would have not invested now will invest. The spread is lower, benefiting buyers and sellers. Work is automated meaning market makers do not have to stand around on the NYSE or CBOE all day - people can sit in their offices, thinking up algorithms, backtesting them etc. (of course the quants doing this are not the same people who had been doing it usually). The old time finance guys have no idea what a back-propagating multilayer neural network is and how it's eating their lunch, and there is resentment and suspicions of foul play. I am more suspicious about the suspicion. You can pitch a tent and set up a hedge fund like Renassiance or DE Shaw without the blessing of an investment bank, and perhaps the banks resent this, despite the fact that they're doing HFT as well.