Axel Hübner tests financial models for a bank

“What can physicists do? ” is an interview series that profiles physicists who opted for careers outside of academia.

What was your PhD research focus?

Condensed-matter theory. I modeled quantum thermal transport in lattices—phonon motion and force constants between atoms.

What were you looking for in a job?

I didn’t like the environment in academia, so I had always planned to go into industry. I had done some internships, and I was looking around. I wanted to use my expertise and to do something challenging.

How did you move into finance?

When I was looking for job possibilities, I got a random suggestion via LinkedIn to consider a position at Deutsche Bank. I sent in my CV. During the interviews, they gave me challenging mathematical tasks. I found it interesting to solve integral equations and partial differential equations. I got hooked. They offered me a job as a model validation specialist.

What do you like about your job at the bank?

We use proper mathematics—not just Excel sheets—so it can be interesting. I like that I can apply what I learned in my studies. And it pays well.

How do you use your physics in your job?

The stock exchange behaves like Brownian motion, and you have algorithms to model the movement and volatility of stocks and interest rates. I test the models for pricing derivatives that the bank sells on the financial market and for products, such as loans, that have a price at a certain interest rate. I use Python coding and mathematics—partial differential equations, statistics, and Monte Carlo simulations. Sometimes you need mathematical intuition to get a feeling of what might go wrong—and test it. And I use my experience evaluating whether results make sense.

Is there anything you’d like to add?

There’s a learning curve at the beginning. You have to learn the lingo and write reports. But after about six months, I got up to speed, and it’s pretty chill. One disappointment is that I have the impression it’s hard to get a promotion on my team; there is no clear path for advancement.