I'm very ignorant when it comes to things like this. So Mark invested in a company? He heard they were going to do a PIPE, he sold his shares, and the next day they fell 10%?

How did he break the law?

Def. Insider Trading: "Illegal trading by anyone considered an insider who has access to non-public information, and who attempts to profit from that knowledge."

I understand that sentence, it makes sense to me, but I don't see how this is unlawful? What if you're working for a company that you're also a shareholder of and you get the "feeling" that the company is going to tank, so you sell... Is that illegal? Or are these different things.