[UltraSane]

Millisecond trading strategies have zero relationship to information about companies or economic fundamentals and are therfore not economically productive. They're exploiting microstructure inefficiencies like latency arbitrage, order front-running, not price discovery. That's not 'teaching' the market it's a tax on everyone else's execution. The fact that it's legal doesn't make it structurally useful. It is just a result of the rules not being updated when trading became automated at superhuman speeds

[KPGv2]

> Millisecond trading strategies have zero relationship to information about companies or economic fundamentals and are therfore not economically productive

It is not clear to me that the only economically productive information is "information about companies or economic fundamentals."

If I know some idiot is willing to pay 100x what a company is actually worth, that is economically productive because it gives me, someone better with money, a ton of resources that formerly were controlled by someone who didn't know how to leverage the assets in an economically productive manner. IT's the same argument as allowing adverse possession: transfer of assets from non-productive owners to productive owners, benefiting society as a whole.

With this, I've established a third kind of data beyond "economic fundamentals" and "information about companies."

[drob518]

Right. “Worth” and “price” are relative notions that are only useful when paired with a point of view. What’s your house “worth?” You might have a number in your head, but unless you have a buyer willing to transact at that price, your house isn’t worth what you think it is. And this relates to economically productive information. Your house might also be worth more if one knows that there is gold or oil buried underneath. It might make more economic sense to bulldoze the house and start mining or drilling.

[UltraSane]

I'm not sure what your comment has to do with HFT