"Only in the exceptional case, where the integrity and competence of the advisers have been thoroughly demonstrated, should the investor act upon the advice of others without understanding and approving the decision made."

Next Quote

There is no reason to feel any shame in hiring someone to pick stocks or mutual funds for you. But there's one responsibility that you must never delegate. You, and no one but you, must investigate whether an adviser is trustworthy and charges reasonable fees.

— Benjamin Graham