Many students and graduates do internships and sometimes go further to pursue a career in an investment bank. I wanted to know: what is the ruling on working in an investment bank?

I also wanted to ask: if one has done a paid internship (a temporary role where one is employed usually over the summer) with an investment bank, what should the individual do with that money? - Since it is impossible almost to give that money back to the bank which employed them.

Finally: are there any particular dua that one can make to keep them away from such employment opportunities (assuming that it is Haram). Again assuming that it is Haram - I am guessing that the ideal thing to do is to do Taubah and to make dua and ask for a better, Halal career ?