"The use of the term front-running in this article is completely inaccurate and is unfortunately becoming standard in reporting around HFT. No HFT sees your ord

"The use of the term front-running in this article is completely inaccurate and is unfortunately becoming standard in reporting around HFT. No HFT sees your order before it trades as a result of a latency advantage, and therefore cannot "front run" it (not to mention the fact that even if they did, they do not have a fiduciary duty to you so they can't front run you by definition)." I don't think the article is saying that they are front running via seeing their order - they are saying that an arbitrage opportunity exists because of the difference in speed of the two data feeds. "Saying you have N number of winning days is largely immaterial as that usually means "trading profit" ie it does not account for the price of doing business and would not be considered profit in other businesses. Also, there are lots of easy to devise schemes for making a little money often, but most of them lose a lot of money occasionally." Oh I agree - of course it doesn't say whether or not are, overall, making money. But that's not the point - they're saying that their systems made money 300+ days in a row. Even if that is a small trading profit, that shouldn't really be statistically possible. But you're right that the numbers may be (and likely are) a PR activity by a given HFT firm as much as anything else. "Finally, HFT profits have already disappeared (at least in the market making space which is where these venue arbitrage volume numbers come from). It is a low margin race to the bottom that is now being propped up via legislation (the sub penny rule in equities)." Interesting - what, specifically, about the sub-penny rule is propping that up?