Updated 19 May 2020
A fund manager is an expert in investment. Their job is to seek out the best investment opportunities for their clients (or the clients of the firm they are working for) within the particular rules that have been imposed upon the funds they are managing. These rules may be imposed by governments (in the form of government legislation), or regulators (financial institutions who may impose financial regulations) or by investors themselves (who may have decided to limit investments to a certain category, e.g. ethical investments).
Fund managers decide things like:
Having decided where to invest the fund, it is the fund manager’s job to continually review their decisions and to adjust the make-up of their fund as circumstances change.