Protect my job security.  “No one ever got fired for buying IBM.”   Institutional investors tend to cluster-invest in the same large funds, even though many studies many studies  show that small funds consistently outperform large funds. This could be because allocators all want access to the best funds.  On the other hand, it could be argued that there is less career risk if allocators follow the crowd and invest in the same funds their peers select; career select;  career  risk is one of the biggest enemies of alpha.