For most institutional funds, notably Pension Funds, their members i.e., employees who are ultimately the principal beneficiaries continuously contribute a portion of their monthly earnings throughout the duration of their employment to the Fund through the appointed administrator. These contributions make their way to the Investment managers who invest these funds in the market as they buy into different securities. The accumulation of these contributions over time is what makes up their fund credits and the lump sum that will be used to purchase an annuity when they retire.