Say I want to work on Wall Street, what should I major in?
It depends on what school you attend, their curriculum and what career you want to pursue, but it could include finance, economics, and/or mathematics.
First get into a school they actually recruit from, second major in finance. Some schools don’t offer finance so econ or accounting. If you can’t get into one of those schools, consider going for undergrad at whatever school and getting an MBA from a top school. Lastly make as close to straight A’s as you can.
Wall Street jobs are hard to come by, especially as an undergrad. It probably is more important to go to a tip tier (Ivy or equivalent) school and very very well than anything else. A number of majors such as finance at Wharton, economics at Harvard, financial engineering at Princeton etc. (to name but a few) would all give you a chance to end up on Wall Street.
^^^ **top (not tip, sorry).