As someone in the industry and in that particular area, it seems like its you who are mistaken. Anyone whose a market maker is playing in the HFT space, otherw

As someone in the industry and in that particular area, it seems like its you who are mistaken. Anyone whose a market maker is playing in the HFT space, otherwise you can't cancel fast enough when the market moves otherwise. Other uses of HFT are interlisted arb that keeps companies that trade in multiple countries at the appropriate non arbitrage price. Or even inter market arb that keeps prices on each exchange in the US at a non arbitrage price. I mean the entire currency market is kept in sync due to HFT. They also do ETF arb that keeps ETF prices at, you guess it, their non arbitrage price. These are all things that were done very poorly before HFT, and well computerization in general of the market. The one thing I find when making these comments is people keep moving the goal posts. Remember: At one point HFT was being able to trade multiple times a minute with a computer. That was HFT at a time in the 80s. Then being able to trade a a second level to keep exchange prices in sync, that was at one time HFT level speed. That was HFT in the 90s. People now take that HFT behaviour for granted and try to move the goal posts to micro second timing forgetting that the above are all hft activities, its just that many more people can do them now. HFT has undeniably shrunk spreads and decreased what the average person pays to buy the market.