Strategy. Under normal circumstances, the Fund invests at least 80% of its net assets (plus any borrowings for investment purposes) in securities included in the underlying index. This policy may be changed without shareholder approval; however, shareholders would be notified upon 60 days notice in writing of any changes. The Fund employs a passive management strategy designed to track, as closely as possible, the performance of the Index. The Fund invests in the common stock of each company in the Index in approximately the same proportion as represented in the Index itself. The Fund may also lend its securities. The Fund may concentrate its investments (i.e., invest 25% or more of its total assets) in a particular industry or group of … Show more… Under normal circumstances, the Fund invests at least 80% of its net assets (plus any borrowings for investment purposes) in securities included in the underlying index. This policy may be changed without shareholder approval; however, shareholders would be notified upon 60 days notice in writing of any changes. The Fund employs a passive management strategy designed to track, as closely as possible, the performance of the Index. The Fund invests in the common stock of each company in the Index in approximately the same proportion as represented in the Index itself. The Fund may also lend its securities. The Fund may concentrate its investments (i.e., invest 25% or more of its total assets) in a particular industry or group of industries if the Index is so concentrated. The degree to which components of the Index represent certain industries may change over time. As of September 30, 2025 , the Index was concentrated in, and therefore the Fund is expected to have significant exposure to, the information technology sector. The Index is composed of common stocks of large companies that operate their businesses in a manner consistent with the Calvert Principles for Responsible Investment (the Calvert Principles) (a copy of which is included as an appendix to the Funds prospectus) and are selected from the universe of the 1,000 largest publicly traded U.S. companies based on market capitalization, excluding business development companies. As described in the Index rules and methodology (available on the Calvert website), and as determined by Calvert Research and Management (Calvert) , Index components must meet certain criteria relating to leadership in talent management practices, which may be evidenced by a diverse workforce or an equal and inclusive work culture, or demonstrate significant improvements in talent management practices. More specifically, the following factors related to leadership in talent management practices are considered: (i) workforce representation ( a gender-balanced workforce among its board members, executives, senior and middle management, and employees; ethnically diverse board members and, where available, executives and management ; and representation of board members on age and cultural background); (ii) career advancement (career opportunities, pipeline ratio, internal mobility and promotion); (iii) pay and compensation (employee compensation and benefits, living wage and pay gap); (iv) work life balance (family support and flexible working); and (v) corporate culture and inclusion . The Calvert Principles serve as a framework for considering environmental, social and governance (ESG) factors. Under this framework, Calvert seeks to identify companies and other issuers that provide positive leadership in the areas of their operations and overall activities that are material to improving long-term shareholder value and societal outcomes, including ESG areas such as: environmental sustainability and resource efficiency; equitable societies and respect for human rights; and accountable governance and transparency. Stocks are weighted in the Index based on their float-adjusted market capitalization tilted towards companies with better talent management practices, subject to certain prescribed limits . As of September 30, 2025 , the Index included 270 companies (and typically is expected to be in the range between 400 and 600 companies), and the market capitalization ranged from approximately $ 3.28 billion to $ 4.53 trillion with a weighted average market capitalization of approximately $ 2 trillion . Market capitalizations of companies within the Index are subject to change. The number of companies in the Index will change over time due to Calverts evaluation of an issuer relative to the Calvert Principles or corporate actions involving companies in the Index, among other things. The Index is reconstituted annually and is rebalanced quarterly. The Index is owned by Calvert, which is an affiliate of the Adviser. ?Christopher Madden, CFA, Co-Head of Applied Responsible Investment Solutions, Yijia Chen, CFA, ESG Quantitative Research Analyst and Index Manager, and Zi Ye, Index Manager, manage the Index construction process at Calvert. An index is a group of securities whose overall performance is used as a standard to measure investment performance. An index or passively managed fund tries to match, as closely as possible, the performance of an established target index. An index funds goal is to mirror the target index whether the index is going up or down. To track the Index as closely as possible, the Fund attempts to remain fully invested in stocks. The Fund uses a replication method of indexing. The replication method involves holding every security in the Index in approximately the same proportion as the Index. Unlike the Index, however, the Fund is subject to certain regulatory requirements that can limit its ability to fully replicate the Index. Under various circumstances, it may not be possible or practicable to purchase or hold all of, or only, the constituent securities in their respective weightings in the Index. If Fund assets should ever decline to below $5 million, the Fund may use the sampling method. The sampling method involves selecting a representative number of securities that will resemble the Index in terms of key risk and other characteristics. Show less