world currencies

Hello, I am currently a M.S. student at Johns Hopkins studying applied and computational math. I went to undergrad studying mathematical finance. My GPA in undergrad is 3.97, and my JHU GPA is about 3.3.... I am not sure if going into statistics or applied math would be right for what I would like to go into for my career. I would like to open my own private equity firm but investing in solely agricultural and green energy companies. Would like to base investment decisions off predominantly quantitative analysis. What would be the best major for this? and what school would be best for this?