[YuriNiyazov]

It goes without saying, but the field of "AI" is kinda massive, with lots and lots of subfields (or, disciplines that used to be subfields but at this point are massive enough to be called fields on their own, such as for example NLP and ML). So, much like in any other discipline, you will find yourself specializing in no time.

The reason I asked about hedge funds is that there seems to be a small army of people with doctorates in Physics working for hedge funds (not necessarily part of a bank). They are mostly in NYC and Greenwich, CT. Various forms of AI (NLP - sentiment analysis, ML - statistical modeling, many others that they keep under wraps) are in wide use.

And, of course, you could always get a job at Google Research.