Curious about your retirement savings? Our How Much Do I Need To Retire? quiz gives you an idea of where you stand and a starting point to think about your long-term planning. — There’s a specific kind of excitement that takes over the markets when a company promises to change the world. It starts with an article shared between colleagues, moves to a text message to your financial advisor, and ends with a very simple question: "How many shares can I buy?" Because when a company is talki...