Here is an article about the events mentioned, that has some more detail: https://www.ft.com/content/17bc0ef6-2282-11ea-92da-f0c92e957a96 https://www.ft.com/con

Here is an article about the events mentioned, that has some more detail: https://www.ft.com/content/17bc0ef6-2282-11ea-92da-f0c92e957a96 https://www.ft.com/content/17bc0ef6-2282-11ea-92da-f0c92e957... > up to 10 seconds before live comments were broadcast on television or internet streams Ten seconds is a long enough time for your "if so," which is what I would guess happens in this specific circumstance. I am an amateur in this space, but in general there are a lot of misconceptions about HFT, because the details are highly technical. See the debates over "paying for order flow," for example. I think it's hard to characterize these systems because, well, they are proprietary. In my understanding, most HFT folks rely on a combination of fundamental and technical analysis, more than sentiment analysis. HFT is more of a game of "make a small amount of money trading all the time" than "wait until some news breaks and reacts to it."