One other aspect of HFT that is good for the general investor is that HFT injects liquidity, making it easier for a general investor to liquidate their position, which is a desirable thing for human traders. HFT does not magically make human investors engage in more or less speculative behavior.
HFT is an easy thing to attack, but I've never encountered a lucid argument for why it's bad. "It's not fair that I'm not as fast" isn't really a reason unless you explain why removing liquidity (i.e., making it harder for you to find a buyer at your price point), paired with you moving up the "trading swiftness" rankings, is preferable.
the common argument against it is that it guarantees a technological arms race and by those conditions pushes the smaller groups out of the competition.
it's unfair in the same vein that the rich are always offered better loan rates than the poor. Yeah, it's obvious why that would be, but it's not fair either.
although imo pushing small-backer arbitrage out of the equation is a good thing.
What HFT arbitrage does is rapidly push markets with different prices into alignment with each other. If you banned HFT but kept multiple markets, the inevitable result would be markets with bigger differences in prices for longer.
The only kind of trading that really good HFT trading pushes out is other slower less efficient arbitrage traders, but why should we want more worse arbitrage traders if the result is markets being more out of sync?
What's important economically is that traders that trade based on fundamentals can do so efficiently across multiple markets. Efficient HFT arbitrage trading helps that, it doesn't hinder it.
> the common argument against it is that it guarantees a technological arms race and by those conditions pushes the smaller groups out of the competition.
But a cursory examination of history would reveal that the literal opposite has happened.
HFT is an easy thing to attack, but I've never encountered a lucid argument for why it's bad. "It's not fair that I'm not as fast" isn't really a reason unless you explain why removing liquidity (i.e., making it harder for you to find a buyer at your price point), paired with you moving up the "trading swiftness" rankings, is preferable.