Why? We already have regulations such as circuit breakers in our markets because unlike what you are claiming, absolute liquidity is not the god you think it is. There can absolutely be such a thing as over-optimization.

They are likely suggesting that incremental, hypothetical increases in market efficiency appear to come at increasingly steep costs which primarily borne by the rest of society at large.

And the evidence for this is … ?

Front-running is an easy example.

So place a limit order.

Do you also preach everyone to learn self-defense when they propose making mugging illegal?

No, in the best world we do both.

Clicking radio button on a website is not at all comparable to learning self defense.

Also, front running is already illegal.

https://www.investopedia.com/terms/f/frontrunning.asp

> Clicking radio button on a website is not at all comparable to learning self defense.

However, stealing money is still stealing money.

> Also, front running is already illegal.

Great! Which means there are sometimes legitimate reasons to clamp down on "hyper-efficient" but socially negative actors.

Front running is illegal.

Finance is 12% of the entire US economy.

What’s the right %?

Clearly less than 12%.

Well, I’m convinced.

What extra liquidity is there for executing trades every microsecond instead of batching them up for thrice a minute trades?