What major would help in being a stock broker?

I want to be a stock broker after college. I was just wondering what major would help in being a stock broker. I plan on taking either Marketing or Commerce. And if after college, can I start on being a stock broker right away? What are the steps that I need to take after college to become a full fledged stock broker?|||finance major with mba preferred, and then u take the securities courses while working to get your license