[roenxi]

It isn't obvious that the retail investors are that excited by sub-second liquidity.

Speaking personally, I'd even be happy to wait several seconds to see if someone else is willing to pay a better price.

[vecter]

That's not how things work. You would see much less demand/supply for a particular stock at every price level, which means you'd pay much more to buy less and would have to pay much more to sell less also. There are no upsides to having fewer market makers.

[roenxi]

> you would see much less demand/supply

Why? If the HFT firm was willing to offer me $X 2 milliseconds ago they are probably still willing to offer $X now. It isn't like there has been time for anything to change; there are going to be short periods of time where there is literally no new information.

And they are just as likely to be offering me more now than less as conditions change.

[gpderetta]

if they weren't able to move their price 2 milliseconds later, they wouldn't offer $X in the first place.