If you are interested in going the route of an entrepreneur/start-up founder, an interesting place to begin would be to explore where these two fields converge.

Ask yourself questions like:

What kind of new technology could improve the world of finance?

What technological tools did you wish you (or your company) had during your career in finance?

Or you could apply your skills in finance to financing technological enterprises. Perhaps look for a job at a VC firm that focuses on tech investments. You could learn more about technological enterprises on the job there, and see where in the tech world you might like to branch out to next.