The upshot of this argument is that this is valuable activity. We need markets to price tradable assets and provide liquidity.
The counterargument is that there are diminishing and/or negative returns to increased liquidity and velocity.
Take just stocks. Liquidity is not a problem. You have liquidity whether trades take minutes or milliseconds. Pricing? I'd say we have pricing covered too, at least the pricing that more/faster algorithmic trading will contribute.
Meanwhile, all this stuff costs money, people, resources that aren't available for actual productive work instead of overhead.
My view is that current liquidity and pricing are far from perfect, particularly when it matters most (e.g. a market panic) and particularly in the global context of the vast universe of interrelated instruments that need better relative pricing. Given that we benefit from realtime pricing, milliseconds matter when you must determine a large vector of prices with complex dependencies using the ensemble recursive system that is the global market.
> And in a market panic, your friendly HFT shop next door is there and offering to buy and sell to stabilise the price?
Some are. It's not that they are friendly, it's just that doing so can be highly profitable if one can estimate the mispricing with a sufficient degree of certainty.
> In which market do we benefit from milliseconds pricing, compared to, say, an auction every minute?
I argue that all of the significant ones benefit. The global market is huge and interrelated in complex ways. There are many trading entities with a variety of specialties. They communicate their expertise through the markets by placing orders. It's an iterative process and a lot of information must be conveyed. The faster the entities can communicate back and forth, the more accurately the prices can represent a weighted consensus. Constraining the trading to 1 minute auctions would reduce the communication bandwidth.
>that aren't available for actual productive work instead of overhead.
That’s a very biased view. Another view would be that improving the efficiency of the largest markets in the world have a much larger positive impact on society than the vast majority of the “productive” work you refer to.
It's biased to the premise, which is that "day trading's" contribution to price efficiency & liquidity are of diminishing value, and that the marginal value is essentially 0 or negative.
The counterargument is that there are diminishing and/or negative returns to increased liquidity and velocity.
Take just stocks. Liquidity is not a problem. You have liquidity whether trades take minutes or milliseconds. Pricing? I'd say we have pricing covered too, at least the pricing that more/faster algorithmic trading will contribute.
Meanwhile, all this stuff costs money, people, resources that aren't available for actual productive work instead of overhead.