By “taking advantage of lags in information flow” you’re actually disseminating information and reducing the lag.

The social value or reducing the price dissemination lag from a microsecond to 110 ns is zero. Hence why the billions of resources going into it are a greater waste than even bitcoin.

If they were noise, they would not be profitable strategies.

I don't want to get caught up in arguing what is noise in the mathematical sense. I think the parent is refering to the fact that the arbitrage traders are not adding any real value by making these trades this fast. The market would adjust in miliseconds. Who really wants to let some guy who built a 825 mile cable be a rent seeker on every trade for all eternity? https://www.businessinsider.com/chicago-stock-exchange-respo...

He's not a rent seeker. Absent his existence, the people on both sides of the trade would be harmed by crossing a bigger spread.

Noise compared to the signal actually needed for a market to function. Markets functioned nicely on much, much longer timeframes in the past.

They also had much higher transaction and information costs.

Is the human allowed to use pencil & paper when reasoning about the stock? A graphing calculator? A spreadsheet program? A numerical SDE solver?

By what rule do you propose limiting other people’s free choice to use computing resources to accelerate the time scale of reasoning about a price?

The "free choice" argument is a charade: the only people with the "freedom" (ie, wealth) to win that race are "people" like Goldman Sachs. On the whole, it's just another legal mechanism for pumping money from the poor to the wealthy. Modern markets could not exist without regulation, which by definition limits freedoms. We're just talking about a sensible regulation that eliminates a pointless misdirection of resources, not unlike laws against gambling.

A lot of HTF shops are comparatively tiny companies (in the order of hundreds or less employees). Large hedge funds and investment banks are relatively late players to the game.

You didn’t address my comment at all. This just seems like some unfounded normative assertions about some other thing entirely.