You can get an idea of this just by using standard funding math. Series E means investors hold 70% give or take. Execs hold 20-25% of the remainder, and rank and file employees have < 5%. One factor here that is meaningful -- original shareholders have taken money off the table, meaning they've given up ownership in the company to investors in exchange for cash. I don't know if that offer was made equally to all shareholders (I've heard a lot of good things about Twilio, so I imagine it was) -- which is why I say < 5% -- the number would be larger otherwise.