Halal Careers in Finance except Islamic Banking

Assalamualaikum, is 'Mergers and Acquisitions ’ a halal career. My son is going to study Commerce/Business with Finance major and it will be good to know which direction to steer his career to, in shaa Allah.Which career options are permissible other than working in Islamic banks which are very few or only one in a city in Australia or western countries.
Appreciate your help. Jazakallahu Khair.

Wasalam

May Allah bless you.
This article might be useful for you to read:

And also in this video of IFG, there is some advice offered by @ibrahimkhan on career in finance.

Check at 31:25mns https://www.youtube.com/watch?v=brkVcMgPmPw

Kind regards