Startups vs banking from a former Techstars COO and Lazard Salesperson

So you have seen the movie social network and think you can make a Mark Zuckerberg and build another Facebook easily? So you are tired of the investment banking finance world but you think you can easily make it in startups as an entrepreneur. Don't be fooled, startups are for no softies, and it's probably not for you.
A Risk so big you cannot comprehend
If you are not on the founding team in a startup the chances of you getting rich easily are close to zero. The risk of you leaving a comfy finance job where you get to move from analyst to associate and to vice president with a constant salary is the good life compared to being in the trenches of a startup.
The founding team
Unless you have thought and created the company and the idea with your partners the chance of you getting founders equity is also close to zero. These are the only guys that are really going to "make it" if the company does well. You may get lucky and be one of the first employees of the company that does IPO but the chances of that are also minimal. Trust me. A career with a bank is easy compared to your chances of really making it big in tech, so stay where you are.