I would bet the bulk of them have a bachelors in Political Science or English from an Ivy, and an MBA from a top 10 business school like Wharton, Harvard Business School, or Stanford Business School.
Most of the value of an MBA is not curriculum, but rather in the networking that two years of taking classes side by side with connected people allows. Similarly, a Political Science major from Harvard can be hired by a major financial firm, when a Finance major from a state school would be passed over.