Pros
FINRA is a mission-driven organization from top to bottom: protecting the investor and the integrity of the financial markets. As such, employees are passionate about their work -- it's not about quarterly profits at all. The salaries and benefits are excellent and there is a strict "workplace respect" policy. It was the first place I ever worked with zero harassment. No bad behavior is allowed here. Excellent workplace for women. Sensible budgets. Transparent employee review processes.
Cons
As a regulator of the securities industry, FINRA has very high standards. FINRA employees are expected to carefully follow established processes and gain approvals in advance. This is not a place where you cut corners, or "ask forgiveness". If you want decisions made quickly, you will be frustrated. Your work must be perfect and you may work long hours.