> Allegedly they were hacking into news services and reading news before it was publicly released, which means their investing time frame was measured in hours

> Allegedly they were hacking into news services and reading news before it was publicly released, which means their investing time frame was measured in hours and minutes. Contrary to an economist's default assumptions, information doesn't travel instantaneously, and not all actors are immediately logical. To put it another way, there's a delay where profitable arbitrage is possible with widely-distributed information because many large players are slow-to-move. In short, there is reaction time - sometimes a 2-4 day window - between when news is released and share prices get where they're going. So those hackers had even more lead time in executing.