You are a big time optimist. The odds of a small company being worth even a fraction of 500 mil 2 years from now is very remote. And, regardless of their perceived value at that time, the stock is worthless unless and until the company goes public. As far as I can tell right now, they are still privately held. Just because they are backed by a venture capital group does not mean they will ever go public. Any time you are served a carrot of stock options in a currently non public company, you need to consider it a remote potential benefit. It should not greatly influence your decision on whether to accept a position or not.