I.e. in a bank of 2 elevators where one is resting on ground and the other is resting on a different floor, as soon as someone calls the ground elevator (which is already there and immediately opens) the other elevator (if idle) will move to the ground floor so that there's no delay the next time someone calls one from the ground floor.

EDIT: I can't read, sorry all!

> > price is usually purely determined by the net inflows and outflows as decided by humans.

> "as decided by humans", more than 90% of trades are led by bots, so no, price is not being determined by humans.

You skipped past the "MMs just smooth it out over time so everyone gets good pricing at the time and in the size they want it" right afterwards which exactly explains why most trading is between bots! Person A wants to buy 10 shares of Y at time T1, Person B wants to sell 20 shares of Y at time T2, Person C wants to buy 10 shares of Y at time T3. Those are all at different times, therefore bots have to take the other side of each trade, then trade with each other to smooth out prices in between each point.

> In fact, we have seen time and again how some weird companies get a huge inflow of purchases simply because of bots misinterpreting news articles.

I actually clearly see this happening more with humans than with bots. Can you think of a single example attributed to bots? A bot that can misinterpret a news article and lose money is fixed and/or disabled forever. There is no shortage of dumb humans willing to lose money due to a lack of literacy.

Market makers and HFT don't determine price: price is usually purely determined by the net inflows and outflows as decided by humans. MMs just smooth it out over time so everyone gets good pricing at the time and in the size they want it.

> Second, there is never any reconciliation of the costs society is saddled with in order to chase arbitrarily more accurate prices

By definition market makers are earning a fraction of the price improvement they provide, ergo the costs to society have to be less that the benefits for better pricing for the companies to stay in business!

> Third, as an index investor, I more or less couldn’t care less

As an index investor you should absolutely care! How do you think you are able to buy into the fund at a reasonable price? And then how do you think the fund is able to rebalance without transaction costs destroying performance long-term?

Why should I trust that your assessment is correct? Is it likely to ever be correct in the case of a doctor/mechanical engineer/athlete/economist/whatever? So why do so many people insist that an incredibly intelligent AI researcher has fallen into some obvious trap?