Strategy. 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 will normally invest at least 95% of its net assets, including borrowings for investment purposes, in securities contained in the Index (the 95% Policy). The Fund may also lend its securities. Calvert US Mid-Cap Core Responsible Index. The Index is composed of the common stocks of mid-size companies that operate their businesses in a manner consistent with The Calvert Principles for Responsible Investment (the Calvert Principles). Mid-size companies are selected from the 1,000 largest publicly … Show more… 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 will normally invest at least 95% of its net assets, including borrowings for investment purposes, in securities contained in the Index (the 95% Policy). The Fund may also lend its securities. Calvert US Mid-Cap Core Responsible Index. The Index is composed of the common stocks of mid-size companies that operate their businesses in a manner consistent with The Calvert Principles for Responsible Investment (the Calvert Principles). Mid-size companies are selected from the 1,000 largest publicly traded ?U.S. companies based on market capitalization, excluding business development companies and approximately the 200 largest publicly traded ?U.S. companies. The Calvert Principles serve as a framework for considering environmental, social and governance (ESG) factors. Stocks are weighted in the Index based on their float-adjusted market capitalization within the relevant sector, subject to certain prescribed limits. The Index is owned by CRM, which also serves as investment adviser to the Fund. Christopher Madden, CFA, Head of Applied Responsible Investment Solutions, and ?Zi Ye, Index Manager, manage the Index construction process at CRM. As of December 31, 2025, the Index included 626 companies, and the market capitalization ranged from approximately $1.7 billion to $75.9 billion with a weighted average market capitalization of $27.5 billion. Market capitalizations of companies within the Index are subject to change. The number of companies in the Index will change over time due to ?CRMs evaluation of an issuer relative to the Calvert Principles or corporate actions involving companies in the Index. The Index is reconstituted annually and is rebalanced quarterly. Indexing. 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. For example, the Fund is subject to diversification and concentration limitations that can require the Funds holdings to materially deviate from 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