The Wellcome Trust derives the vast majority of its income from a diverse portfolio of investments, valued at £13.9 billion (as at 30 September 2006). An innovative bond issue launched in 2006 will add to the Wellcome Trust's funding power over the coming years.

In effect, the Wellcome Trust is using the bond to borrow money from other financial institutions. It undertakes to pay a fixed amount of interest to the lender over the period of the bond and reinvests the sums borrowed. As the interest rate is relatively low, investment returns should comfortably exceed the interest paid.

Because of the Trust's strong financial basis and long-term perspective it is judged to be a low-risk option for investors. The Trust received the highest possible bond credit ratings, Aaa from Moody's and AAA from Standard & Poor's.

The bond issue proved highly popular, enabling the Trust to increase the value of the bonds issued to £550m.