Investing client funds?

Question for the experienced readers. I am currently studying finance in College and I am looking for a professional role that would involve trading/investing in financial markets and Wealth management seems like it might be the right one for me. 

When you work in a Bulge bracket bank, what markets (asset classes) do most wealth managers invest in? I read that most people who invest or trade stocks lose money, does that include wealth managers? If yes, what separates the the ones who are successful at investing or trading equities from the ones who arent?

Do you guys also read books about investing? Or does the job have trainings on the asset classes and then some wealth managers simply understand the concepts better?

Thank you!