Former Wall Street trader and financial content creator Vivian Tu (who goes by the handle Your Rich BFF) recently shared her opinion about joint bank accounts in a YouTube short. Many people combine finances with their spouse when they get married, and some end up with only one bank account between them, meaning all the money they each earn (and spend) flows in and out of that account. While this certainly sounds convenient, especially when it comes to paying joint bills that may cost more than each person can afford on their own (like a mortgage payment), Vivian Tu isn't a fan -- and she has good reasons.