Attracting flows by attracting big clients

We explore a new channel for attracting inflows using a unique dataset of corporate 401(k) retirement plans and their mutual fund family trustees. Families secure substantial inflows by being named trustee of a 401(k) plan. This affords the plan sponsor potential influence on the family's portfolio decisions. Consistent with this, we find that family trustees significantly overweight their 401(k) client firm's stock. Trustee overweighting is more pronounced when the conflict of interest of the trustee family is more severe and when other mutual funds are selling the client firm's stock. This overweighting is not explained by superior information. We quantify a potentially large benefit to the 401(k) sponsor firm of having its price propped up by its trustee fund's more severe overweighting. We also estimate the resulting loss to mutual fund investors, which can be large in some cases.