DUSB aims to optimize returns by investing in US investment-grade securities that have ultra-short maturities. The portfolio mainly focuses on securities that mature in less than a year but may also increase exposure to those with longer maturities when opportunity for higher yields arises. The fund diversifies across various types of fixed income securities, including US government and agency obligations, foreign bonds, corporate obligations, and more. It primarily invests in certificates of deposit, commercial paper, bankers acceptances, notes, and bonds perceived to be of high-quality. DUSB aims to maintain a portfolio maturity of one year or less, adjusting the fund's investment focus based on expected term premiums. Additionally, the fund may utilize futures contracts, options and securities lending to manage interest rate exposure and generate more income. Being actively managed, investment decisions are made at the discretion of the Adviser and may result in a higher degree of portfolio turnover.