Calvert Mid Cap Fund 1

Q2 2018 INVESTMENT COMMENTARY Calvert Mid Cap Fund 1 A:CCAFX C:CCACX I:CCPIX The Fund invests primarily in mid cap, U.S. stocks whose market capitalization falls within the range of the Russell Midcap Index. The Fund s investment approach focuses on fundamental research, including consideration of responsible investing criteria as well as growth, earnings, industry position and other criteria. Key Takeaways Despite heightened tensions around the possibility of a U.S. China trade war, U.S. equities finished higher during the quarter on the back of strong corporate earnings and positive economic data. For the second quarter, Calvert Mid Cap Fund ended in positive territory, outperforming the benchmark Russell Midcap Index, which returned 2.82%. positive territory, outperforming the benchmark Russell Midcap Index, which returned 0.46%. The Fund outperformed the Index primarily due to positive stock selection in nearly all 11 GICS sectors. Negative sector allocation and security selection in the materials sector partially offset the Fund s outperformance. CALVERT S APPROACH TO RESPONSIBLE INVESTING WHO WE ARE Calvert Research and Management is a recognized leader in Responsible Investing. Our mission is to deliver superior long term performance to our clients and to enable them to achieve positive impact. WHAT WE OFFER Serving financial advisors and their clients, as well as a wide array of institutional investors, Calvert s investment strategies feature integrated environmental, social, and governance (ESG) research and corporate engagement. HOW WE STAND APART At Calvert Research and Management, our integrated responsible investment approach sets us apart from many other investment managers. YOUR MANAGEMENT TEAM CALVERT RESEARCH AND MANAGEMENT (ADVISOR) Charles Gaffney Vice President, Calvert Research and Management Joined Calvert Research and Management 2016 Managed Fund since 2016 MARKET OVERVIEW Mounting fears of a global trade war constrained stock markets in the second quarter of 2018. President Trump s imposition of tariffs drew retaliatory moves from impacted countries, ranging from China to Canada to the European Union. U.S. stocks began the period on the upswing amid strong economic data. The unemployment rate dipped below 4% for the first time in nearly two decades, while other indicators, such as manufacturing and construction activity, also gained. Reacting to continued growth, the U.S. Federal Reserve (Fed) raised its benchmark interest rate in June for the second time in 2018 to a range of 1.75% to 2.0%. MARKET BENCHMARKS Quarter ended 06/30/2018 MAJOR GLOBAL EQUITY INDICES VALUE CORE GROWTH S&P 500 1.40% 3.43% 5.25% Russell 1000 1.18% 3.57% 5.76% Russell 2000 8.30% 7.75% 7.23% MSCI EAFE 2.64% 1.24% 0.11% MSCI Emerging Markets 8.94% 7.96% 7.01% Source: S&P, Russell, MSCI

Q2 2018 Calvert Mid Cap Fund 1 Investment Commentary 2 After peaking in early June, however, the broad stock market turned down for the remainder of the three month period. Notably, rising trade tensions hurt stocks of several large U.S. multinational companies. On the positive side, energy and technology stocks bucked the downward trend and recorded solid gains for the period. Energy stocks benefited from rising crude oil prices. Overseas, investors sold European stocks, as trade war worries threatened the region s fragile economic recovery. In China, a prolonged stock market slump reached bear market territory in late June. Besides trade war fears, signs of slowing economic growth also weighed on Chinese stocks. Amid investor caution, global stock markets recorded mixed results for the second quarter. The Dow Jones Industrial Average, which includes several large multinational companies, managed a 1.26% advance for the three month period. The broader S&P 500 Index rose 3.43%. The technology laden Nasdaq Index topped all major U.S. stock indexes, gaining 6.31% for the second quarter. Overseas, the MSCI EAFE Index of mostly European stocks returned 1.24%, while the MSCI Emerging Markets Index fell 7.96%. Small cap stocks generally outperformed their large cap counterparts in the period. In terms of investing style, growth stocks topped value stocks among large cap stocks, while value stocks edged growth among small cap issues. PERFORMANCE REVIEW For the second quarter, Calvert Mid Cap Fund (the Fund) outpaced the benchmark Russell Midcap Index (the Index), which returned 2.82%. The Fund s outperformance was driven by positive stock selection in the health care, consumer staples and financials sectors. Part of that outperformance was offset by negative sector allocation and security selection in the materials sector. CONTRIBUTORS Business momentum for social media company Twitter (TWTR) was strong during the quarter as the company sought to continue to keep pace with some of its large competitors within the online advertising market. The stock was also added to the S&P 500 Index during the quarter, further increasing its visibility to investors. With oil prices continuing to trend higher, offshore projects become more economical for exploration and production companies, such as Oceaneering International (OII). As a dominant player in the remotely operated vehicles segment, the company is well positioned to benefit as project spending for offshore drilling operations comes back. Cotiviti Holdings (COTV), a health care technology company, saw a sharp positive reaction in its stock price as Verscend Technologies, a private equity backed health care analytics company, announced its intentions to acquire the business at a sizeable premium. DETRACTORS In addition to releasing weaker guidance for next year, Symantec (SYMC), a cyber security company, announced a surprise internal investigation into its accounting policies. Both of these negatively impacted the stock during the quarter. First American Financial (FAF) underperformed during the quarter as rising interest rates and concerns about the end of the housing cycle weighed on the title insurance company s shares. We continue to favor the less volatile exposure the company gives us to the housing industry, which we believe could strengthen from here. Disappointing organic growth numbers dragged down shares of after market auto parts provider LKQ Corporation (LKQ) early in the quarter. In addition, comments and concerns about tariffs continued to pressure the entire automotive space.

Q2 2018 Calvert Mid Cap Fund 1 Investment Commentary 3 PORTFOLIO CHARACTERISTICS as of 06/30/2018 Weighted Average Market Cap 14.5B 14.8B Number of Holdings 89 793 Price/Earnings (LTM) 23.6x 20.6x Price/Earnings (NTM) 18.0x 17.1x Price/Book 2.9x 2.6x Historic EPS Growth (3yr) 9.3% 9.7% ROA 6.8% 5.8% BENCHMARK LT Debt/Capital 41.9% 42.3% GICS SECTORS VS. BENCHMARK 2 SECTOR RUSSELL MIDCAP INDEX DIFFERENCE Consumer Discretionary 12.83% 14.26% 1.43% Consumer Staples 5.69% 4.45% 1.24% Energy 3.81% 5.35% 1.54% Financials 14.60% 13.81% 0.79% Health Care 10.87% 9.61% 1.26% Industrials 12.61% 13.55% 0.94% Information Technology 16.81% 18.19% 1.38% Materials 6.34% 5.41% 0.93% Real Estate 8.80% 8.90% 0.10% Telecom Services 0.43% 0.43% Utilities 5.62% 6.04% 0.42% Cash 2.03% 2.03% TOP 10 HOLDINGS (%) 2, 3 Ball Corp 2.18 Extra Space Storage Inc 2.02 National Retail Properties Inc 1.91 AvalonBay Communities Inc 1.82 Fiserv Inc 1.66 VF Corp 1.65 CMS Energy Corp 1.60 GoDaddy Inc 1.50 Parker Hannifin Corp 1.48 First American Financial Corp 1.48 MARKET OUTLOOK Economic growth in the U.S. appears to be picking up steam as we enter into the second half of the year. The unemployment rate continues to decline, consumer spending has been improving and many individuals and corporations are still reaping the benefits of U.S. tax reform. Those positive forces could help fuel additional strength in corporate profits, providing an attractive environment for U.S. equities. However, the current investment landscape is not without risks. Inflationary pressures are mounting within the U.S. economy, which could lead to additional interest rate hikes by the Fed, and rising trade protectionism could undoubtedly lead to increased volatility. Those concerns, coupled with the fact that we have entered the tenth year of the current equity bull market, warrant a heightened sense of caution among investors. As was the case in the first quarter, we believe that selectivity will be extremely important as the year progresses. We believe that prudent security selection is vital in any market environment, but even more so in one that includes so much uncertainty around interest rates, inflation, public policy and other geopolitical issues. As such, we will continue to seek out stocks with solid business models and sustainability practices, quality management teams, strong earnings prospects and attractive valuations.

Q2 2018 Calvert Mid Cap Fund 1 Investment Commentary 4 % AVERAGE ANNUAL RETURNS (AS OF 06/30/2018) Q2 YTD 1 YEAR 3 YEARS 5 YEARS 10 YEARS A Shares at NAV 4.84 5.11 11.63 3.51 8.48 7.63 I Shares at NAV 4.96 5.33 12.08 3.94 9.02 8.32 A Shares with Max. 4.75% Sales Charge 0.15 0.12 6.34 1.84 7.43 7.11 Benchmark 1 2.82 2.35 12.33 9.57 12.21 10.22 Benchmark 2 3.16 5.40 18.52 10.72 13.36 10.45 Benchmark 1:Russell Midcap Index Benchmark 2:Russell Midcap Growth Index Past performance is no guarantee of future results. Investment return and principal value will fluctuate so that shares, when redeemed, may be worth more or less than their original cost. Performance is for the stated time period only; due to market volatility, the Fund s current performance may be lower or higher than quoted. For the Fund s performance as of the most recent month end, please refer to eatonvance.com. Returns are historical and are calculated by determining the percentage change in net asset value (NAV) with all distributions reinvested. Returns for other classes of shares offered by the Fund are different. Performance less than or equal to one year is cumulative. The minimum investment is $1,000 for A Shares and $250,000 for I Shares. Minimums may be waived in certain situations. Please see the prospectus for additional information. FACTS A Shares Inception 10/31/1994 I Shares Inception 06/03/2003 Performance Inception 10/31/1994 Class A Expense Ratio 4 Gross: 1.34% Net: 1.21% Class I Expense Ratio 4 Gross: 0.88% Net: 0.86%

Q2 2018 Calvert Mid Cap Fund 1 Investment Commentary 5 Effective December 31, 2016, Eaton Vance Distributors, Inc. replaced Calvert Investment Distributors, Inc. as the Fund s principal underwriter following the acquisition by Calvert Research and Management ( CRM ) of substantially all the business assets of Calvert Investment Management, Inc. ( CIM ). CRM has also replaced CIM as the investment adviser to the Fund. See the Fund s updated prospectus dated January 3, 2017. Portfolio characteristics exclude 3 securities in Calvert s High Impact Investments program, which represented 1.233% of the portfolio as of 06/30/2018. High Social Impact Investments are investments that, in the Adviser s opinion, offer the opportunity for significant sustainability and social impact. These investments are generally illiquid and involve high risks. See the Fund s prospectus for details and calvert.com for a complete list of Fund holdings. 1 Prior to 11/06/2017, Fund was called Calvert Capital Accumulation Fund. 2 Percent of total net assets. Portfolio profile subject to change due to active management. Percentages may not total 100% due to rounding. 3 Top 10 Holdings excludes cash and equivalents. 4 Source: Fund prospectus. Net expense ratio reflects a contractual expense reimbursement that continues through 1/31/19. Without the reimbursement, if applicable, performance would have been lower. The views expressed in this report are those of portfolio manager(s) and are current only through the date stated at the top of this page. These views are subject to change at any time based upon market or other conditions, and Eaton Vance disclaims any responsibility to update such views. These views may not be relied upon as investment advice and, because investment decisions are based on many factors, may not be relied upon as an indication of trading intent on behalf of any Eaton Vance fund. This commentary may contain statements that are not historical facts, referred to as forward looking statements. The Fund s actual future results may differ significantly from those stated in any forward looking statement, depending on factors such as changes in securities or financial markets or general economic conditions, the volume of sales and purchases of Fund shares, the continuation of investment advisory, administrative and service contracts, and other risks discussed from time to time in the Fund s filings with the Securities and Exchange Commission. Index Definitions: Russell Midcap Index is an unmanaged index of U.S. mid cap stocks. Russell Midcap Growth Index is an unmanaged index of U.S. midcap growth stocks. S&P 500 Index is an unmanaged index of large cap stocks commonly used as a measure of U.S. stock market performance. Russell 1000 Value Index is an unmanaged index of U.S. large cap value stocks. Russell 1000 Index is an unmanaged index of 1,000 U.S. large cap stocks. Russell 1000 Growth Index is an unmanaged index of U.S. large cap growth stocks. Russell 2000 Value Index is an unmanaged index of U.S. small cap value stocks. Russell 2000 Index is an unmanaged index of 2,000 U.S. small cap stocks. Russell 2000 Growth Index is an unmanaged index of U.S. small cap growth stocks. MSCI EAFE Index is an unmanaged index of equities in the developed markets, excluding the U.S. and Canada. MSCI Emerging Markets Index is an unmanaged index of emerging markets common stocks. MSCI indexes are net of foreign withholding taxes. Source: MSCI. MSCI data may not be reproduced or used for any other purpose. MSCI provides no warranties, has not prepared or approved this report, and has no liability hereunder. Dow Jones Industrial Average is a price weighted average of 30 blue chip stocks that are generally the leaders in their industry. NASDAQ Composite Index is a market capitalization weighted index of all domestic and international securities listed on NASDAQ. Source: Nasdaq, Inc. The information is provided by Nasdaq (with its affiliates, are referred to as the Corporations ) and Nasdaq s third party licensors on an as is basis and the Corporations make no guarantees and bear no liability of any kind with respect to the information or the Fund. Unless otherwise stated, index returns do not reflect the effect of any applicable sales charges, commissions, expenses, taxes or leverage, as applicable. It is not possible to invest directly in an index. Historical performance of the index illustrates market trends and does not represent the past or future performance of the fund. About Risk: The value of investments held by the Fund may increase or decrease in response to economic, and financial events (whether real, expected or perceived) in the U.S. and global markets. The value of equity securities is sensitive to stock market volatility. Smaller companies are generally subject to greater price fluctuations, limited liquidity, higher transaction costs and higher investment risk than larger, more established companies. Investing primarily in responsible investments carries the risk that, under certain market conditions, the Fund may underperform funds that do not utilize a responsible investment strategy. No fund is a complete investment program and you may lose money investing in a fund. The Fund may engage in other investment practices that may involve additional risks and you should review the Fund prospectus for a complete description. Calvert funds are available at NAV for RIAs and Wrap Programs. Not all share classes are available to all investors. See a fund s prospectus for details. For more information on any Calvert fund, please contact your financial advisor or visit calvert.com for a free summary prospectus and/or prospectus. An investor should consider the investment objectives, risks, charges, and expenses of an investment carefully before investing. The summary prospectus and prospectus contain this and other information. Read them carefully before you invest or send money. 2018 Eaton Vance Distributors, Inc. Member FINRA/SIPC Two International Place, Boston, MA 02110 800.836.2414 eatonvance.com 23923 7.23.18