First, I'm sure they thought the probability of being caught, and thus the risk to themselves, was low. And who knows? They may have even been right about this

First, I'm sure they thought the probability of being caught, and thus the risk to themselves, was low. And who knows? They may have even been right about this -- without knowing how many people get away with insider trading, it's impossible to say. Second, nearly all of the profits were allegedly made by Joon Jun and Junwoo Chon, who did not work at Netflix. $3M over 3 years was probably a lot of money for them, as it would be for most people.