alt Hacker NewsOn net I'd agree, with the caveat that the hyper speed liquidity comes at the cost of fragility. Liquidity that can disappear in a microsecond can and does amplify market shocks.
As for retail execution, while on net there's a standard and strong argument that a less regulated market is the most efficient, retail execution is most definitely at the bottom of the totem pole, with an order shopped around to parties that can pick and choose the profitable orders before it is sent to wider liquidity pools. I think that this side of the debate is more about evening out the playing field. On net the market may get less efficient, while slower speed participants have an improved experience. These aren't contradictory.
> while slower speed participants have an improved experience
Wall Street lobbies to ban HFT every few years, hoping people who don’t like how it looks will back them up.
Slower participants in equities are block traders. Folks moving hundreds of millions if not billions at a time. Large institutional investors. Dealers. Retail, on the other hand, would get hosed, though it would also become much more profitable to execute, so maybe that brings some service perks for larger retail traders.