Strategy. The Fund seeks to achieve its investment objective by investing, under normal circumstances, at least 80% of its net assets (including borrowings for investment purposes) in a portfolio of floating-rate securities (e.g., corporate floating-rate securities) and securities with durations of less than or equal to one year (80% Policy). The Fund is not a money market fund and does not seek to maintain a stable net asset value. Under normal circumstances, the Funds average portfolio duration will be less than one year. The Fund generally defines ultra-short duration securities as those with ?durations of less than or equal to one year. The Fund typically invests at least 85% of its net assets in investment grade, ?U.S. dollar-denominated debt securities, as … Show more… The Fund seeks to achieve its investment objective by investing, under normal circumstances, at least 80% of its net assets (including borrowings for investment purposes) in a portfolio of floating-rate securities (e.g., corporate floating-rate securities) and securities with durations of less than or equal to one year (80% Policy). The Fund is not a money market fund and does not seek to maintain a stable net asset value. Under normal circumstances, the Funds average portfolio duration will be less than one year. The Fund generally defines ultra-short duration securities as those with ?durations of less than or equal to one year. The Fund typically invests at least 85% of its net assets in investment grade, ?U.S. dollar-denominated debt securities, as assessed at the time of purchase. A debt security is considered investment grade when assigned a credit quality rating of BBB- or higher by S&P Global Ratings (S&P) or an equivalent rating by another nationally recognized statistical rating organization (NRSRO), including Moodys Investors Service or Fitch Ratings, or Kroll Bond Rating Agency, LLC for securitized debt instruments only (such as asset-backed securities (ABS) and mortgage-backed securities (MBS))) or if unrated, considered to be of comparable credit quality by the Funds investment adviser. For purposes of rating restrictions, if securities are rated differently by two or more rating agencies, the highest rating is used. The Fund invests principally in bonds issued by ?U.S. corporations, the U.S. Government or its agencies, and U.S. government-sponsored enterprises (GSEs) such as the Federal National Mortgage Association (FNMA) and the Federal Home Loan Mortgage Corporation (FHLMC). The Fund also may invest in trust preferred securities, money market instruments, taxable municipal obligations and loans. The Fund may invest in ?ABS and MBS that represent interests in pools of mortgage loans (MBS) or other assets (ABS) assembled for sale to investors by various U.S. governmental agencies, government-related organizations and private issuers. MBS may include collateralized mortgage obligations (CMOs) and commercial mortgage-backed securities (CMBS). Under normal circumstances, the Fund will invest in below-investment grade, high-yield debt instruments (commonly known as junk bonds), including distressed instruments that are in default. The Funds investment in such instruments is limited to 15% of its net assets. The Fund may also invest up to 25% of its net assets in foreign debt securities. Foreign debt securities include American Depositary Receipts (ADRs), which are either sponsored or unsponsored and Global Depositary Receipts (GDRs). The Fund may engage in forward foreign currency exchange contracts to seek to hedge against the decline in the value of currencies in which its portfolio holdings are denominated against the U.S. dollar. The Fund may also lend its securities. Investment decisions for the Fund are made primarily on the basis of fundamental and quantitative research conducted by the investment advisers research staff and consideration of the responsible investment criteria described below. Management of the Fund involves consideration of numerous factors (such as quality of business franchises, financial strength, management quality and security structural and collateral considerations). The portfolio managers may also use sector rotation and relative value strategies in their management of the Fund. The portfolio managers may sell a security when the investment advisers valuation target is reached, the fundamentals of the investment change or to pursue more attractive investment options. A security will also be sold (in accordance with the investment advisers guidelines and at a time and in a manner that is determined to be in the best interests of shareholders) if the investment adviser determines that the issuer does not operate in a manner consistent with the Funds responsible investment criteria. The portfolio managers intend to focus on risk management and also seek to preserve capital to the extent consistent with the Funds investment objective. The Fund intends to seek to manage investment risk by maintaining broad issuer and industry diversification among its holdings, and by utilizing fundamental analysis of risk/return characteristics in securities selection. The Fund seeks to manage duration and any hedging of interest rate risk through the purchase and sale of ?U.S. Treasury securities and related futures contracts (which are a type of derivative instrument). Responsible Investing. The portfolio manager(s) seek to invest in companies that manage environmental, social and governance (ESG) risk exposures adequately and that are not exposed to excessive ESG risk through their principal business activities. Companies are analyzed by the investment advisers ESG analysts utilizing The Calvert Principles for Responsible Investment (Principles), a framework for considering ESG factors (a copy of which is included as an appendix to the Funds Prospectus). Each company is evaluated relative to an appropriate peer group based on material ESG factors as determined by the investment adviser. Pursuant to the Principles, the investment adviser seeks to identify companies and other issuers that operate in a manner that is consistent with or promotes environmental sustainability and resource efficiency, equitable societies and respect for human rights, and accountable governance and transparency. The Fund generally invests in issuers that are believed by the investment adviser to operate in accordance with the Principles and may also invest in issuers that the investment adviser believes are likely to operate in accordance with the Principles pending the investment advisers engagement activity with such issuer. Show less