Being able to afford the money which humans cost is easy. Being able to afford the time which humans cost is not so easy. The optimal strategy might be to trade within a few microseconds based on "something happened to this company, so something is likely to happen to its stock price", then trade a bit more a few milliseconds later based on "a computer thinks that this sounds like good news", and then make a third trade a few seconds later based on "a human pushed the (green|red) button when they saw the headline".