[nichtich]

When it's hard to draw the line from outside, prosecutors mostly try to prove their cases from the inside communications. If you email your coworker: "Guess what I found ... AMD can go bankrupt over this ..." and then short the stock it should be fine. But if you write "Let's put together an action plan to drive the AMD price down" then you would be in trouble. The FX scandal is an perfect example of this. It's true you can explain your action in perfectly legitimate reasons but you can't also call your self "The Cartel" in group chats.

I'm not a lawyer.