This makes a lot of sense to me. What actual economic value is being captured by HFT?
If you're going to give people electronic access to the markets, there's not really any sense in saying they aren't allowed to use whatever computer technology they see fit to trade with that access, as long as they aren't actually manipulating the market.
As far as economic value, it has different uses to different players on the market. Speculators can take advantage of increasingly fleeting arbitrage opportunities, yes. But the flip side of that is that institutional investors can use it defensively, to make it harder to find and exploit those arbitrage opportunities.
That basic game of cat-and-mouse has existed for centuries, and, here, almost 2 decades into the 21st century, it seems absurd to me to say that, of all the places people use technology to do things faster, nobody should be allowed to do it in this one particular case. Which when you get down to it, is essentially what people are suggesting when they say that high frequency trading is bad.
If it stills seem unfair to you (and that's an entirely legitimate feeling), I'd submit that it isn't that that using technology is unfair in and of itself, so much as that technology has the potential to magnify the effects of unfairness that was already baked into the financial system to begin with.
HFT allows better-connected traders to front-run you. You don't get the best price because the HFT guy extracted risk-free profits for himself at your expense.
Front running is accomplished by HFT, but not all HFT is front running. HFT is simply the ability to execute trades quickly on new information, like earnings reports, fed meeting notes, etc. HFT back in the 17th century would simply have been having the fastest couriers and horses to carry news, now it's having the fastest software and data connections. HFT has a couple beneficial sides too, as it tightens the bid/ask spread.
Basically don't confuse a technology that can be used for bad purposes, to be the problem, blame the brokers and the regulators that allow it to happen.
HFT adds nothing to the markets of value[1] and lowers the value average players are able to extract.
[1] except liquidity which they usually don't add in a useful manner, they will tend to make highly liquid stocks more liquid while not adding any liquidity to stocks that are being harmed by illiquidity.
In statistical expectation, you are better off not selling your stock to an HFT market maker. They are only buying from you, on average, when the spread you pay is more than they expect the stock to move. You could wait and sell to someone else for a tiny bit more, on average.
In statistical expectation, you are better off not insuring your car. The insurance company writes the policy such that their expected payout over its lifetime is less than the premiums they collect.
But real people don't live in the world of maximizing expected value. The guy selling his stocks is doing it a couple times a year, and doesn't want to risk losing a few % if the market gaps down, just to make a tenth of a penny more in expectation. Nobody wants to take out another car loan if their shiny new SUV gets hit driving out of the dealership. Bearing risks people don't want is valuable.
So bizarrely, while these services may satisfy a need, consumers are only really happy when the provider loses. Nobody looks back on decades of crash-free driving reminiscing about paying those insurance premiums. Nobody likes to sell stock and see it tick up.
(And I'm hand waving assuming you're a randomly selected trader or driver. If you have inside information, trading with anyone is positive EV. If you drive drunk at 100mph but have no tickets or DUIs on your record, insuring your car is positive EV.
I'm also hand waving away comparative advantage. That better price an HFT market maker gets when turning over your trade may not be achievable for you. Maybe they can trade on more exchanges or predict prices better to get out at the right time. They do this all day so trading optimally is not a waste of their time, but it's probably a waste of yours. In that case, you may lose more and take more risk doing it yourself. I think that's closer to reality.)
You are also better off selling into a market containing at least on HFT market maker. Without them, spreads become fat. It is notable that the principle aggressors, at the political level and until recently, when HFT became an armchair economics term of art, against HFT were the old line market makers.
I no longer work in HFT. You can do everything better, smarter, faster than ever, and make less. It is one of the most brutally capitalist businesses: orders on exchanges are a pure undifferentiated commodity. The guy making the smallest spread fastest gets the trade. [1] Nobody cares if it's Virtu or Citadel or three guys in their garage. Think of a business like Wal-Mart's, but if someone finds a way to sell soap a half-cent cheaper, you sell 0 and go out of business.
And for the end users of the markets, that's great. Let these guys compete to make tighter markets or arbitrage prices sooner. HFTs play an intermediation role, helping other traders transfer risk immediately to lock in a guaranteed price, rather than waiting for someone else to trade with them. They're basically like CarMax or a grocery store: research what things are worth, buy at wholesale prices, sell at retail prices, and control inventory risk.
1: https://meanderful.blogspot.com/2013/01/hfts-dirty-little-se...
I speak up here because it irritates me to see them maligned by people who know what they're talking about.