Nuveen Senior Income Fund (the Fund) is a closed-end management investment company. The Fund's investment objective is to achieve a high level of current income, consistent with capital preservation. The Fund invests 80% of its total assets in adjustable rate senior secured loans. The Fund may invest up to 20% of its total assets in the United States dollar- denominated senior loans of non- United States borrowers, senior loans that are not secured, other debt securities, and equity securities and warrants acquired in connection with the Fund's investment in senior loans. The Fund is authorized to invest in derivative financial instruments, including forwards, futures, options and swap transactions. The Fund's investment manager is Nuveen Asset Management Inc. The sub-advisor of the Fund is Symphony Asset Management, LLC.