CALAMOS GLOBAL DYNAMIC INCOME FUND ANNUAL REPORT   7

best-utilized long-term within asset allocations, we believe that NAV return is the better measure of a fund’s performance. However, when managing the fund, we strongly consider actions and policies that we believe will optimize its overall price performance and returns based on market price.

SINCE INCEPTION MARKET PRICE AND NAV HISTORY THROUGH 10/31/20

Performance data quoted represents past performance, which is no guarantee of future results. Current performance may be lower or higher than the performance quoted. The principal value of an investment will fluctuate so that your shares, when sold, may be worth more or less than their original cost. Returns at NAV reflect the deduction of the Fund’s management fee, debt leverage costs and all other applicable fees and expenses. You can obtain performance data current to the most recent month end by visiting www.calamos.com.

Please discuss the Fund’s distributions during the one-year period.

We employ a level rate distribution policy within this Fund with the goal of providing shareholders a consistent distribution stream. In each month of the period, the Fund distributed $0.0700 per share, resulting in a current annualized distribution rate of 10.77% of market price as of October 31, 2020.

We believe that both the Fund’s distribution rate and level remained attractive and competitive, as low interest rates have limited yield opportunities in much of the marketplace. For example, as of October 31, 2020, the dividend yield of S&P 500 Index stocks averaged approximately 1.72%. Yields were also low within the U.S. government bond market, with the 10-year U.S. Treasury and 30-year U.S. Treasury yielding 0.88% and 1.65%, respectively.

What factors influenced performance over the reporting period?

The Fund maintained its exposure to the equity markets, and its allocations to both convertibles and high yield bonds provided income to the portfolio for the period. The strength and performance of the global convertible market especially buoyed NAV performance for the period. Price performance, however, was muted relative to the advancements of the underlying portfolio due to high levels of market volatility throughout 2020, spurred by concerns regarding the continuity of distribution levels, tax loss selling, the impact of US elections on markets, and the eventual reopening of the economy in the wake of COVID-19.

The Fund has the ability to invest in a range of strategies including convertible securities, high yield, U.S. equities, international equities, and convertible arbitrage. This enables us to participate in a myriad of opportunities on behalf of our shareholders. Given this flexibility, we were able to maintain our exposure to the equity markets through our convertible holdings, which enabled us to participate in the general upward trajectory of equities. Broad improvements in both domestic and global equity as well as fixed income markets contributed to the Fund’s strong performance over the period.

8   CALAMOS GLOBAL DYNAMIC INCOME FUND ANNUAL REPORT

The Fund’s U.S. equity sleeve outperformed relative to the S&P 500 Index as selection and an overweight in consumer discretionary (casinos and gaming), contributed to performance. In addition, our selection in communication services (interactive media and services) was additive.

Conversely, our general underweight in utilities but an overweight in electric utilities impeded performance relative to the index. In addition, our selection in industrials (aerospace and defense) was not helpful.

The Fund’s global equity sleeve outperformed relative to the MSCI World Index. Our selection and overweight in consumer discretionary, namely in automobile manufacturers, was helpful. Our overweight and selection in communication services, especially in interactive media services, also proved beneficial.

Conversely, our selection and underweight in materials, an avoidance of industrial gases, weighed on performance. In addition, our selection in utilities, specifically in multi-sector utilities, also weighed on results.

The Fund’s international sleeve outperformed relative to the MSCI EAFE Index. Our overweight and selection in materials, specifically an overweight in gold, was beneficial relative to the index. In addition, selection and an overweight in communication services, namely an overweight in interactive home entertainment, was helpful.

Conversely, an underweight and selection in information technology, although specifically in technology hardware, storage and peripherals, impeded performance relative to the MSCI EAFE Index. In addition, our overweight in energy, notably in oil & gas exploration & production, was detrimental to performance.

The convertible arbitrage portion benefited from increasing volatility and a significant increase in new convertible issuance. According to ICE BofA, $90.1 billion of new convertible issuance was brought to market in 2020 through October 31. This amount far surpassed the $53.1 billion in the full calendar year 2019 and put 2020 on pace to exceed the most new issuance witnessed since before 1998. The new convertibles issued during the period were attractive for convertible arbitrage as they represented the balanced portion of the market, which when combined with elevated volatility, increased opportunities for trade rebalancing. In addition, much of the new issuance was brought to market at a discount to the convertible’s theoretical valuation, providing an opportunity for pricing arbitrage.

How is the Fund positioned?

We continued to find opportunities across asset classes. We maintained a preference for larger-cap, growth-oriented companies with global presence and geographically diversified revenue streams to offset the economic impact of COVID-19. We believe that such companies are particularly well positioned to capitalize on selective global and overall U.S. growth trends we see as the global economy begins to recover from the impact of Covid-19. In keeping with an emphasis on risk management, we focus on companies that we believe have respectable balance sheets, solid free cash flows, and good prospects for sustainable growth as a result of increasing consumer confidence and fiscal stimulus as they are able to provide reliable debt servicing.

The portfolio’s largest allocations—in absolute terms—reside in the information technology, consumer discretionary and communication services sectors.

We believe that these sectors should be poised to perform well as technology offers solutions to help people across the global economy work and socialize virtually out of

CALAMOS GLOBAL DYNAMIC INCOME FUND ANNUAL REPORT   9

necessity. We believe that the global consumer will benefit from increased stimulus and the release of pent-up demand as the global economy begins to reopen in the wake of COVID-19.

Concerning communication services, we believe that companies in the sector should benefit from improving economic conditions highlighted by higher employment, improved consumer sentiment and relatively low interest rates. This sector should also benefit from an increasingly virtual work and social environment in the wake of COVID-19. Conversely, we are maintaining relatively low exposures to utilities and consumer staples, which we believe may be fully valued at this point in the cycle.

As noted, we pursue a risk-managed approach to total return, though the Fund’s portfolio includes a blend of high-yield and investment-grade credits. We take a very selective approach to unrated securities credits, ever mindful of suitability for our closed-end fund clients. We believe it is particularly important to favor companies that offer the best prospects for reliable debt servicing.

We believe that this is an environment that is conducive to the prudent use of leverage as a means to enhance total return and supporting the fund’s distribution rate. Over the period, our use of leverage enjoyed a favorable reinvestment dynamic. As of October 31, 2020, our approximate amount of leveraged assets was 31%.

What are your closing thoughts for Fund shareholders?

Given our outlook for a more balanced economic recovery—as COVID-19 is soon mitigated with vaccines, and the impact of the U.S. election on markets achieves clarity—we are favoring quality-growth companies poised to participate in the optimism and spending power of the U.S. consumer. Moreover, we are emphasizing investments in businesses with solid cash-flow generation and stronger balance sheets. However, we are mindful of increased volatility, and our active management is imperative to managing risk and optimizing opportunities.

From a thematic and sector perspective, we see opportunities in the technology and consumer services sectors as a more virtual world continues to advance post COVID-19. We believe that health care companies tied largely to vaccines and disease prevention will perform well. We also hold an optimistic view of consumer discretionary stocks; we believe they are favorably valued and positioned to grow revenues given the improved wellbeing of the U.S consumer and further fiscal stimulus. We also favor cyclicals that have lagged much of the initial recovery in 2020, but can now participate in a more balanced recovery. However, we are cautious about companies in the consumer staples sector, which may be fully valued because investors flock to those stocks for income rather than growth. We believe that the high issuance of convertibles will continue to present opportunities in a broader array of sectors and geographical locales.

We believe our active investment approach positions us to take advantage of the volatility and opportunities in global equities and convertible securities. We emphasize risk-managed returns, especially as we expect continued volatility spawned by geopolitical issues to continue into 2021.

The Fund’s use of derivative instruments involves investment risks and transaction costs to which the Fund would not be subject absent the use of these instruments and, accordingly, may result in losses greater than if they had not been used. Derivative instruments can be illiquid, may disproportionately increase losses and may have a potentially large impact on Fund performance.

10   CALAMOS GLOBAL DYNAMIC INCOME FUND ANNUAL REPORT

The Fund’s Investment Objective, Principal INVESTMENT Strategies and Principal Risks; and Important Updates About the Fund

Investment Objective

The Fund’s investment objective is to generate a high level of current income with a secondary objective of capital appreciation.

Principal Investment Strategies

Under normal circumstances, the Fund will invest primarily in a globally diversified portfolio of convertible instruments, common and preferred stocks, and income-producing securities such as investment grade and below investment grade (high yield/high risk) debt securities. The Fund may also incorporate other income-producing strategies, including options, swaps and other derivative instruments, for both investment and hedging purposes. The Fund, under normal circumstances, will invest at least 40% of its managed assets in securities of foreign issuers in developed and emerging markets, including debt and equity securities of corporate issuers and debt securities of government issuers. “Managed assets” means the Fund’s total assets (including any assets attributable to any leverage that may be outstanding) minus total liabilities (other than debt representing financial leverage).

The Fund will maintain a balanced approach to geographic portfolio diversification. The Fund may invest up to 100% of its managed assets in securities of foreign issuers in developed and emerging markets, including debt and equity securities of corporate issuers and debt securities of government issuers.

The Fund will use a number of investment strategies to achieve its objectives and expects to invest in a wide variety of financial instruments. These instruments include global convertible, exchangeable instruments, as well as “synthetic” convertible instruments. The Fund will also invest in global equities or equity-linked securities with high income potential. From time to time, the Fund expects to invest in Rule 144A securities, foreign exchange contracts or securities with imbedded foreign exchange hedges, and high yield bonds of companies rated BB or lower.

In general, the Fund intends to seek out companies with a long-term track record of high dividend payout consistent with dividend growth. In certain circumstances, the Fund may invest in underlying companies it believes have substantial prospects for price appreciation even if the there is little or no dividend growth potential. The Fund may from time to time, seek to sell index options or single stock options (either listed or “over the counter”) to enhance the overall yield of the Fund or, in the opinion of the Adviser, reduce portfolio volatility. The Fund may purchase options to hedge or engage in other hedging activities including the purchase or sale of futures, swaps or options on equities, indices, currencies, interest rates or credits.

The Fund may seek to generate income from option premiums by writing (selling) options. The Fund may write (sell) call options (i) on a portion of the equity securities in the Fund’s portfolio and (ii) on broad-based securities indices or certain ETFs (exchange traded funds) that trade like common stocks but seek to replicate such market indices.

The Fund currently uses financial leverage. The Fund has obtained financial leverage (i) under an Amended and Restated Liquidity Agreement with State Street Bank and Trust Company (“SSB Agreement”) that allows the Fund to borrow up to $265 million and (ii) through the issuance of three series of Mandatory Redeemable Preferred Shares (“MRPS” or “MRP Shares”) with an aggregate liquidation preference of $65 million.

Principal Risks

Management Risk. Calamos’ judgment about the attractiveness, relative value or potential appreciation of a particular sector, security or investment strategy may prove to be incorrect.

Portfolio Selection Risk. The value of your investment may decrease if the investment adviser’s judgment about the attractiveness, value or market trends affecting a particular security, issuer, industry or sector or about market movements is incorrect.

Equity Securities Risk. Equity investments are subject to greater fluctuations in market value than other asset classes as a result of such factors as the issuer’s business performance, investor perceptions, stock market trends and general economic conditions. Equity securities are subordinated to bonds and other debt instruments in a company’s capital structure in terms of priority to corporate income and liquidation payments. The Fund may invest in preferred stocks and convertible securities of any rating, including below investment grade.

CALAMOS GLOBAL DYNAMIC INCOME FUND ANNUAL REPORT   11

Below investment grade securities or comparable unrated securities are considered predominantly speculative with respect to the issuer’s ability to pay interest and principal and are susceptible to default or decline in market value due to adverse economic and business developments. The market values for below investment grade securities tend to be very volatile, and these securities are generally less liquid than investment- grade debt securities. For these reasons, your investment in the Fund is subject to the following specific risks:

•increased price sensitivity to changing interest rates and to a deteriorating economic environment;

•greater risk of loss due to default or declining credit quality;

•adverse company specific events are more likely to render the issuer unable to make interest and/or principal payments; and

•if a negative perception of the below investment grade market develops, the price and liquidity of below investment grade securities may be depressed. This negative perception could last for a significant period of time.

Emerging Markets Risk. Emerging market countries may have relatively unstable governments and economies based on only a few industries, which may cause greater instability. The value of emerging market securities will likely be particularly sensitive to changes in the economies of such countries. These countries are also more likely to experience higher levels of inflation, deflation or currency devaluations, which could adversely affect the value of the Fund’s investments and hurt those countries’ economies and securities markets.

Foreign Securities Risk. Investments in non-U.S. issuers may involve unique risks compared to investing in securities of U.S. issuers. These risks are more pronounced to the extent that the Fund invests a significant portion of its non-U.S. investments in one region or in the securities of emerging market issuers. These risks may include:

•less information may be available about non-U.S. issuers or markets due to less rigorous disclosure or accounting standards or regulatory practices in foreign jurisdictions;

•many non-U.S. markets are smaller, less liquid and more volatile. In a changing market, Calamos may not be able to sell the Fund’s portfolio securities at times, in amounts and at prices it considers reasonable;

•an adverse effect of currency exchange rate changes or controls on the value of the Fund’s investments;

•the economies of non-U.S. countries may grow at slower rates than expected or may experience a downturn or recession;

•economic, political and social developments may adversely affect the securities markets in foreign jurisdictions, including expropriation and nationalization;

•the difficulty in obtaining or enforcing a court judgment in non-U.S. countries;

•restrictions on foreign investments in non-U.S. jurisdictions;

•difficulties in effecting the repatriation of capital invested in non-U.S. countries;

•withholding and other non-U.S. taxes may decrease the Fund’s return; and

•dividend income the Fund receives from foreign securities may not be eligible for the special tax treatment applicable to qualified dividend income.

Based upon the Fund’s test for determining whether an issuer is a “foreign issuer” as described above, it is possible that an issuer of securities in which the Fund invests could be organized under the laws of a foreign country, yet still conduct a substantial portion of its business in the U.S. or have substantial assets in the U.S. In this case, such a “foreign issuer” may be subject to the market conditions in the U.S. to a greater extent than it may be subject to the market conditions in the country of its organization.

Debt Securities Risk. The Fund may invest in debt securities, including corporate bonds and high yield securities. In addition to the risks described elsewhere in the Fund's prospectus (such as high yield securities risk and interest rate risk), debt securities are subject to certain additional risks, including issuer risk and reinvestment risk. Issuer risk is the risk that the value of debt securities may decline for a number of reasons which directly relate to the issuer, such as management performance, leverage and reduced demand for the issuer’s goods and services. Reinvestment risk is the risk that income from the Fund’s portfolio will decline if the Fund invests the proceeds from matured, traded or called bonds at market interest rates that are below the Fund portfolio’s current earnings rate. A decline in income could affect the market price of the Fund’s common shares or the overall return of the Fund.

12   CALAMOS GLOBAL DYNAMIC INCOME FUND ANNUAL REPORT

Convertible Securities Risk. The value of a convertible security is influenced by both the yield of non- convertible securities of comparable issuers and by the value of the underlying common stock. The value of a convertible security viewed without regard to its conversion feature (i.e., strictly on the basis of its yield) is sometimes referred to as its “investment value.” A convertible security’s investment value tends to decline as prevailing interest rate levels increase. Conversely, a convertible security’s investment value tends to increase as prevailing interest rate levels decline.

However, a convertible security’s market value tends to reflect the market price of the common stock of the issuing company when that stock price is greater than the convertible security’s “conversion price.” The conversion price is defined as the predetermined price at which the convertible security could be exchanged for the associated stock. As the market price of the underlying common stock declines, the price of the convertible security tends to be influenced more by the yield of the convertible security and changes in interest rates. Thus, the convertible security may not decline in price to the same extent as the underlying common stock. In the event of a liquidation of the issuing company, holders of convertible securities would be paid before the company’s common stockholders.

Non-Convertible Income Securities Risk. The Fund will also invest in non-convertible income securities. The Fund’s investments in non-convertible income securities may have fixed or variable principal payments and all types of interest rate and dividend payment and reset terms, including fixed rate, adjustable rate, zero coupon, contingent, deferred, payment in kind and auction rate features. Recent events in the fixed-income markets, including the potential impact of the Federal Reserve Board tapering its quantitative easing program, may expose the Fund to heightened interest rate risk and volatility as a result of a rise in interest rates. In addition, the Fund is subject to the risk that interest rates may exhibit increased volatility, which could cause the Fund’s net asset value (“NAV”) to fluctuate more. A decrease in fixed-income market maker capacity may act to decrease liquidity in the fixed-income markets and act to further increase volatility, affecting the Fund’s return.

Derivatives Risk. Generally, derivatives are financial contracts whose value depends on, or is derived from, the value of an underlying asset, reference rate or index, and may relate to individual debt or equity instruments, interest rates, currencies or currency exchange rates, commodities, related indices and other assets. The Fund may utilize a variety of derivative instruments including, but not limited to, interest rate swaps, convertible securities, synthetic convertible instruments, options on individual securities, index options, long calls, covered calls, long puts, cash-secured short puts and protective puts for hedging, risk management and investment purposes.

The Fund’s use of derivative instruments involves investment risks and transaction costs to which the Fund would not be subject absent the use of these instruments and, accordingly, may result in losses greater than if they had not been used. The use of derivative instruments may have risks including, among others, leverage risk, volatility risk, duration mismatch risk, correlation risk, liquidity risk, interest rate risk, credit risk, management risk and counterparty risk. Derivatives also involve the risk of mispricing or improper valuation and the risk that changes in the value of a derivative may not correlate perfectly with an underlying asset, interest rate or index. Suitable derivative transactions may not be available in all circumstances and there can be no assurance that the Fund will engage in these transactions to reduce exposure to other risks when that would be beneficial.

Furthermore, the skills needed to employ derivatives strategies are different from those needed to select portfolio securities and, in connection with such strategies, the Fund makes predictions with respect to market conditions, liquidity, currency movements, market values, interest rates and other applicable factors, which may be inaccurate. Thus, the use of derivative investments may require the Fund to sell or purchase portfolio securities at inopportune times or for prices below or above the current market values, may limit the amount of appreciation the Fund can realize on an investment or may cause the Fund to hold a security that it might otherwise want to sell. Tax rules governing the Fund’s transactions in derivative instruments may also affect whether gains and losses recognized by the Fund are treated as ordinary or capital, accelerate the recognition of income or gains to the Fund, defer losses to the Fund, and cause adjustments in the holding periods of the Fund’s securities, thereby affecting, among other things, whether capital gains and losses are treated as short-term or long-term. These rules could therefore affect the amount, timing and/or character of distributions to shareholders. In addition, there may be situations in which the Fund elects not to use derivative investments that result in losses greater than if they had been used.

Amounts paid by the Fund as premiums and cash or other assets held in margin accounts with respect to the Fund’s derivative instruments would not be available to the Fund for other investment purposes, which may result in lost opportunities for gain.

Derivative instruments can be illiquid, may disproportionately increase losses and may have a potentially large impact on Fund performance.

CALAMOS GLOBAL DYNAMIC INCOME FUND ANNUAL REPORT   13

Risks Associated with Options. There are several risks associated with transactions in options. For example, there are significant differences between the securities markets and options markets that could result in an imperfect correlation among these markets, causing a given transaction not to achieve its objectives. A decision as to whether, when and how to use options involves the exercise of skill and judgment, and even a well- conceived transaction may be unsuccessful to some degree because of market behavior or unexpected events. The Fund’s ability to utilize options successfully will depend on Calamos’ ability to predict pertinent market movements, which cannot be assured.

The Fund may sell options on individual securities and securities indices. All call options sold by the Fund must be “covered.” Even though the Fund will receive the option premium to help protect it against loss, a call option sold by the Fund exposes the Fund during the term of the option to possible loss of opportunity to realize appreciation in the market price of the underlying security or instrument and may require the Fund to hold a security or instrument that it might otherwise have sold. In addition, a loss on a call option sold may be greater than the premium received. The Fund may purchase and sell put options on individual securities and securities indices. In selling put options, there is a risk that the Fund may be required to buy the underlying security at a disadvantageous price above the market price. The Fund may purchase and sell put options on individual securities and securities indices. In selling put options, there is a risk that the Fund may be required to buy the underlying security at a disadvantageous price above the market price.

Currency Risk. To the extent that the Fund invests in securities or other instruments denominated in or indexed to foreign currencies, changes in currency exchange rates bring an added dimension of risk. Currency fluctuations could negatively impact investment gains or add to investment losses. Although the Fund may attempt to hedge against currency risk, the hedging instruments may not always perform as the Fund expects and could produce losses. Suitable hedging instruments may not be available for currencies of emerging market countries. The Fund’s investment adviser may determine not to hedge currency risks, even if suitable instruments appear to be available.

Credit Risk. An issuer of a fixed income security could be downgraded or default. If the Fund holds securities that have been downgraded, or that default on payment, the Fund’s performance could be negatively affected.

Default Risk. Default risk refers to the risk that a company that issues a convertible or debt security will be unable to fulfill its obligations to repay principal and interest. The lower a debt security is rated, the greater its default risk. The Fund may incur cost and delays in enforcing its rights against the defaulting issuer.

Recent Market Events. In the past decade, financial markets throughout the world have experienced increased volatility, depressed valuations, decreased liquidity and heightened uncertainty and turmoil. This turmoil resulted in unusual and extreme volatility in the equity and debt markets, in the prices of individual securities and in the world economy. Events that have contributed to these market conditions include, but are not limited to, major cybersecurity events, geopolitical events (including wars, terror attacks and public health emergencies), measures to address budget deficits, downgrading of sovereign debt, declines in oil and commodity prices, dramatic changes in currency exchange rates, and public sentiment. In addition, many governments and quasi-governmental entities throughout the world have responded to the turmoil with a variety of significant fiscal and monetary policy changes, including, but not limited to, direct capital infusions into companies, new monetary programs and dramatically lower interest rates.

The recent spread of an infectious respiratory illness caused by a novel strain of coronavirus (“COVID-19”) has caused volatility, severe market dislocations and liquidity constraints in many markets, including markets for the securities the Fund holds, and may adversely affect the Fund's investments and operations. The transmission of this coronavirus and efforts to contain its spread have resulted in travel restrictions and disruptions, closed international borders, enhanced health screenings at ports of entry and elsewhere, disruption of and delays in healthcare service preparation and delivery, quarantines, event and service cancellations or interruptions, disruptions to business operations (including staff furloughs and reductions) and supply chains, and a reduction in consumer and business spending, as well as general concern and uncertainty that has negatively affected the economy. These disruptions have led to instability in the market place, including equity and debt market losses and overall volatility, and the jobs market. The impact of this coronavirus, and other epidemics and pandemics that may arise in the future, could affect the economies of many nations, individual companies and the market in general in ways that cannot necessarily be foreseen at the present time. In addition, the impact of infectious diseases in developing or emerging market countries may be greater due to less established health care systems. Health crises caused by the recent coronavirus outbreak may exacerbate other pre-existing political, social and economic risks in certain countries. The impact of the outbreak may be short term or may last for an extended period of time.

14   CALAMOS GLOBAL DYNAMIC INCOME FUND ANNUAL REPORT

While the extreme volatility and disruption that U.S. and global markets experienced for an extended period of time beginning in 2007 and 2008 had, until the recent coronavirus outbreak, generally subsided, uncertainty and periods of volatility still remained, and risks to a robust resumption of growth persisted. Federal Reserve policy, including with respect to certain interest rates may adversely affect the value, volatility and liquidity of dividend and interest paying securities. Market volatility, dramatic changes to interest rates and/or a return to unfavorable economic conditions may lower the Fund’s performance or impair the Fund’s ability to achieve its investment objective.

In June 2016, the United Kingdom approved a referendum to leave the European Union (“EU”) (“Brexit”). On March 29, 2017, the United Kingdom formally notified the European Council of its intention to leave the EU and commenced the formal process of withdrawing from the EU. The withdrawal agreement entered into between the United Kingdom and the EU entered into force on January 31, 2020, at which time the United Kingdom ceased to be a member of the EU. Following the withdrawal, there will be an eleven-month transition period, ending December 31, 2020, during which the United Kingdom will negotiate its future relationship with the EU. Brexit has resulted in volatility in European and global markets and could have negative long-term impacts on financial markets in the United Kingdom and throughout Europe. There is considerable uncertainty about the potential consequences for Brexit, how it will be conducted, how negotiations of trade agreements will proceed, and how the financial markets will react, and as this process unfolds, markets may be further disrupted. Given the size and importance of the United Kingdom’s economy, uncertainty about its legal, political, and economic relationship with the remaining member states of the EU may continue to be a source of instability. Moreover, other countries may seek to withdraw from the European Union and/or abandon the euro, the common currency of the EU.

A number of countries in Europe have suffered terror attacks, and additional attacks may occur in the future. Ukraine has experienced ongoing military conflict; this conflict may expand and military attacks could occur elsewhere in Europe. Europe has also been struggling with mass migration from the Middle East and Africa. The ultimate effects of these events and other socio-political or geographical issues are not known but could profoundly affect global economies and markets.

As a result of political and military actions undertaken by Russia, the U.S. and the EU have instituted sanctions against certain Russian officials and companies. These sanctions and any additional sanctions or other intergovernmental actions that may be undertaken against Russia in the future may result in the devaluation of Russian currency, a downgrade in the country’s credit rating, and a decline in the value and liquidity of Russian securities. Such actions could result in a freeze of Russian securities, impairing the ability of a fund to buy, sell, receive, or deliver those securities. Retaliatory action by the Russian government could involve the seizure of US and/or European residents’ assets, and any such actions are likely to impair the value and liquidity of such assets.

Any or all of these potential results could have an adverse/recessionary effect on Russia’s economy. All of these factors could have a negative effect on the performance of funds that have significant exposure to Russia. In addition, policy and legislative changes in the United States and in other countries are changing many aspects of financial regulation. The impact of these changes on the markets, and the practical implications for market participants, may not be fully known for some time. Widespread disease and virus epidemics, such as the recent coronavirus outbreak, could likewise be highly disruptive, adversely affecting individual companies, sectors, industries, markets, currencies, interest and inflation rates, credit ratings, investor sentiment, and other factors affecting the value of the Fund’s investments.

Market Disruption Risk. Certain events have a disruptive effect on the securities markets, such as terrorist attacks, war and other geopolitical events, earthquakes, storms and other disasters. The Fund cannot predict the effects of similar events in the future on the U.S. economy or any foreign economy.

Market Discount Risk. The Fund’s common shares may trade at a premium or at a discount in relation to NAV. Shares of closed-end investment companies frequently trade at a discount from NAV, but in some cases trade above NAV. The risk of the common shares trading at a discount is a risk separate from the risk of a decline in the Fund’s NAV as a result of investment activities. The Fund’s NAV may be reduced immediately following this offering by the offering costs for common shares or other securities, which will be borne entirely by all common shareholders. The Fund’s common shares are designed primarily for long-term investors, and you should not purchase common shares if you intend to sell them shortly after purchase.

Whether shareholders will realize a gain or loss upon the sale of the Fund’s common shares depends upon whether the market value of the shares at the time of sale is above or below the price the shareholder paid, taking into account transaction costs for the shares, and is not directly dependent upon the Fund’s NAV. Because the market value of the Fund’s common shares will be determined by factors such as the relative demand for and supply of the shares in the market, general market conditions and other factors beyond the control of the Fund, the Fund cannot predict whether its common shares will trade at, below or above NAV, or below or above the public offering price for the common shares.

CALAMOS GLOBAL DYNAMIC INCOME FUND ANNUAL REPORT   15

Leverage Risk. The Fund has issued indebtedness and preferred shares and may borrow money or issue debt securities as permitted by the 1940 Act. As of October 31, 2020, the Fund has leverage in the form of borrowings under the SSB Agreement and outstanding MRP Shares. Leverage is the potential for the Fund to participate in gains and losses on an amount that exceeds the Fund’s investment. The borrowing of money or issuance of debt securities and preferred shares represents the leveraging of the Fund’s common shares. As a non-fundamental policy, the Fund may not issue preferred shares or borrow money and/or issue debt securities with an aggregate liquidation preference and aggregate principal amount exceeding 38% of the Fund’s managed assets as measured at the time of borrowing or issuance of the new securities. However, the Board of Trustees reserves the right to issue preferred shares or debt securities or borrow to the extent permitted by the 1940 Act and the Fund’s policies.

Leverage creates risks which may adversely affect the return for the holders of common shares, including:

•the likelihood of greater volatility in the NAV and market price of the Fund’s common shares;

•fluctuations in the dividend rates on any preferred shares borne by the Fund or in interest rates on borrowings and short-term debt;

•increased operating costs, which are effectively borne by common shareholders, may reduce the Fund’s total return; and

•the potential for a decline in the value of an investment acquired with borrowed funds, while the Fund’s obligations under such borrowing or preferred shares remain fixed.

In addition, the rights of lenders and the holders of preferred shares and debt securities issued by the Fund will be senior to the rights of the holders of common shares with respect to the payment of dividends or to the payment of assets upon liquidation. Holders of preferred shares have voting rights in addition to and separate from the voting rights of common shareholders. The holders of preferred shares or debt, if any, on the one hand, and the holders of the common shares, on the other, may have interests that conflict in certain situations.

Leverage is a speculative technique that could adversely affect the returns to common shareholders. Leverage can cause the Fund to lose money and can magnify the effect of any losses. To the extent the income or capital appreciation derived from securities purchased with funds received from leverage exceeds the cost of leverage, the Fund’s return will be greater than if leverage had not been used. Conversely, if the income or capital appreciation from the securities purchased with such funds is not sufficient to cover the cost of leverage or if the Fund incurs capital losses, the return of the Fund will be less than if leverage had not been used, and therefore the amount available for distribution to common shareholders as dividends and other distributions will be reduced or potentially eliminated.

The Fund will pay, and common shareholders will effectively bear, any costs and expenses relating to any borrowings and to the issuance and ongoing maintenance of preferred shares or debt securities. Such costs and expenses include the higher management fee resulting from the use of any such leverage, offering and/or issuance costs, and interest and/or dividend expense and ongoing maintenance. These conditions may, directly or indirectly, result in higher leverage costs to common shareholders.

Certain types of borrowings may result in the Fund being subject to covenants in credit agreements, including those relating to asset coverage, borrowing base and portfolio composition requirements and additional covenants that may affect the Fund’s ability to pay dividends and distributions on common shares in certain instances. The Fund may also be required to pledge its assets to the lenders in connection with certain types of borrowings. The Fund may be subject to certain restrictions on investments imposed by guidelines of and covenants with rating agencies which may issue ratings for the preferred shares or short-term debt instruments issued by the Fund. These guidelines and covenants may impose asset coverage or portfolio composition requirements that are more stringent than those imposed by the 1940 Act. The Board of Trustees reserves the right to change the amount and type of leverage that the Fund uses, and reserves the right to implement changes to the Fund’s borrowings that it believes are in the long-term interests of the Fund and its shareholders, even if such changes impose a higher interest rate or other costs or impacts over the intermediate, or short-term time period. There is no guarantee that the Fund will maintain leverage at the current rate, and the Board of Trustees reserves the right to raise, decrease, or eliminate the Fund’s leverage exposure.

If the Fund’s ability to make dividends and distributions on its common shares is limited, such limitation could, under certain circumstances, impair the ability of the Fund to maintain its qualification for taxation as a regulated investment company or to reduce or eliminate tax at the Fund level, which would have adverse tax consequences for common shareholders. To the extent that

16   CALAMOS GLOBAL DYNAMIC INCOME FUND ANNUAL REPORT

the Fund is required, in connection with maintaining 1940 Act asset coverage requirements or otherwise, or elects to redeem any senior securities or prepay any borrowings, the Fund may need to liquidate investments to fund such redemptions or prepayments. Liquidation at times of adverse economic conditions may result in capital loss and reduce returns to common shareholders.

Because Calamos’ investment management fee is a percentage of the Fund’s managed assets, Calamos’ fee will be higher if the Fund is leveraged and Calamos will have an incentive to be more aggressive and leverage the Fund. Consequently, the Fund and Calamos may have differing interests in determining whether to leverage the Fund’s assets. Any additional use of leverage by the Fund would require approval by the Board. In considering whether to approve the use of additional leverage, the Board would be presented with all relevant information necessary to make a determination whether or not additional leverage would be in the best interests of the Fund, including information regarding any potential conflicts of interest.

In considering whether to approve the use of additional leverage through those means, the Board would be presented with all relevant information necessary to make a determination whether or not additional leverage would be in the best interests of the Fund, including information regarding any potential conflicts of interest.

Effects of Leverage. The SSB Agreement provides for credit availability for the Fund, such that it may borrow up to $265.0 million. As of October 31, 2020, the Fund had utilized $153.3 million of the $265.0 million available under the SSB Agreement ($68.1 million in borrowings outstanding, and $85.2 million in structural leverage consisting of collateral received from State Street Bank and Trust Company in connection with securities on loan). Interest on the SSB Agreement is charged on the drawn amount at the rate of Overnight LIBOR plus 0.80%, payable monthly in arrears. Interest on overdue amounts or interest on the drawn amount paid during an event of default will be charged at Overnight LIBOR plus 2.80%. These rates represent floating rates of interest that may change over time. The SSB Agreement has a commitment fee of 0.10% of any undrawn amount. As of October 31, 2020, the interest rate charged under the SSB Agreement was 0.88%. “Net income” payments related to cash collateral in connection with securities lending were 0.44% of the borrowed amount on an annualized basis as of that date, although this amount can vary based on changes in underlying interest rates.

The Fund’s MRP Shareholders are entitled to receive monthly cash dividends, at a currently effective dividend rate per annum for each series of MRP Shares as follows (subject to adjustment as described in the Fund's prospectus: 3.70% for Series A MRP Shares, 4.00% for Series B MRP Shares and 4.24% for Series C MRP Shares.

To cover the interest expense on the borrowings under the SSB Agreement (including “net income” payments made with respect to borrowings offset by collateral for securities on loan) and the dividend payments associated with the MRP Shares, based on rates in effect on October 31, 2020, the Fund’s portfolio would need to experience an annual return of 0.69% (before giving effect to expenses associated with senior securities).

Leverage is a speculative technique that could adversely affect the returns to common shareholders. Leverage can cause the Fund to lose money and can magnify the effect of any losses. To the extent the income or capital appreciation derived from securities purchased with funds received from leverage exceeds the cost of leverage, the Fund’s return will be greater than if leverage had not been used. Conversely, if the income or capital appreciation from the securities purchased with such funds is not sufficient to cover the cost of leverage or if the Fund incurs capital losses, the return of the Fund will be less than if leverage had not been used, and therefore the amount available for distribution to common shareholders as dividends and other distributions will be reduced or potentially eliminated.

The Fund will pay, and common shareholders will effectively bear, any costs and expenses relating to any borrowings and to the issuance and ongoing maintenance of preferred shares, including the MRP Shares, or debt securities. Such costs and expenses include the higher management fee resulting from the use of any such leverage, offering and/or issuance costs, and interest and/or dividend expense and ongoing maintenance.

Certain types of borrowings may result in the Fund being subject to covenants in credit agreements, including those relating to asset coverage, borrowing base and portfolio composition requirements and additional covenants that may affect the Fund’s ability to pay dividends and distributions on common shares in certain instances. The Fund may also be required to pledge its assets to the lenders in connection with certain types of borrowings. The Fund may be subject to certain restrictions on investments imposed by guidelines of and covenants with rating agencies for the preferred shares or short-term debt instruments issued by the Fund. These guidelines and covenants may impose asset coverage or portfolio composition requirements that are more stringent than those imposed by the 1940 Act.

CALAMOS GLOBAL DYNAMIC INCOME FUND ANNUAL REPORT   17

The following table illustrates the hypothetical effect on the return to a holder of the Fund’s common shares of the leverage obtained by us (and utilized on October 31, 2020). The purpose of this table is to assist you in understanding the effects of leverage. As the table shows, leverage generally increases the return to common shareholders when portfolio return is positive and greater than the cost of leverage and decreases the return when the portfolio return is negative or less than the cost of leverage. The figures appearing in the table are hypothetical and actual returns may be greater or less than those appearing in the table.

(1)Includes interest expense on the borrowings under the SSB Agreement, accrued at the interest rate in effect on October 31, 2020 of 0.88%, and dividend expense on the MRP Shares.

Reduction of Leverage Risk.  The Fund has previously taken, and may in the future take, action to reduce the amount of leverage it employs. Reduction of the leverage employed by the Fund, including by redemption of preferred shares, will in turn reduce the amount of assets available for investment in portfolio securities. This reduction in leverage may negatively impact our financial performance, including our ability to sustain current levels of distributions on common shares.

The Board reserves the right to change the amount and type of leverage that the Fund uses, and reserves the right to implement changes to the Fund’s borrowings that it believes are in the best long-term interests of the Fund, even if such changes impose a higher interest rate or other costs or impacts over the intermediate, or short-term time period. There is no guarantee that the Fund will maintain leverage at the current rate, and the Board reserves the right to raise, decrease, or eliminate the Fund’s leverage exposure.

Interest Rate Risk. In addition to the risks discussed above, debt securities, including high yield securities, are subject to certain risks, including:

•if interest rates go up, the value of debt securities in the Fund’s portfolio generally will decline;

•during periods of declining interest rates, the issuer of a security may exercise its option to prepay principal earlier than scheduled, forcing the Fund to reinvest in lower yielding securities. This is known as call or prepayment risk. Debt securities frequently have call features that allow the issuer to repurchase the security prior to its stated maturity. An issuer may redeem an obligation if the issuer can refinance the debt at a lower cost due to declining interest rates or an improvement in the credit standing of the issuer;

•during periods of rising interest rates, the average life of certain types of securities may be extended because of slower than expected principal payments. This may lock in a below market interest rate, increase the estimated period until the security is paid in full and reduce the value of the security. This is known as extension risk;

•rising interest rates could result in an increase in the cost of the Fund’s leverage and could adversely affect the ability of the Fund to meet asset coverage requirements with respect to leverage;

•variable rate securities generally are less sensitive to interest rate changes but may decline in value if their interest rates do not rise as much, or as quickly, as interest rates in general. When the Fund holds variable rate securities, a decrease in market interest rates will adversely affect the income received from such securities and the NAV of the Fund’s shares; and

•the risks associated with rising interest rates may be particularly acute in the current market environment because market interest rates are currently near historically low levels. Thus, the Fund currently faces a heightened level of interest rate risk, especially since the Federal Reserve Board has ended its quantitative easing program and has begun, and may continue, to raise interest rates. To the extent the Federal Reserve Board continues to raise interest rates, there is a risk that interest rates across the financial system may rise. Increases in volatility and interest rates in the fixed-income market may expose the Fund to heightened interest rate risk.

Many financial instruments use or may use a floating rate based on LIBOR, which is the offered rate for short-term Eurodollar deposits between major international banks. On July 27, 2017, the head of the United Kingdom’s Financial Conduct Authority announced a desire to phase out the use of LIBOR by the end of 2021. On November 30, 2020, the administrator of LIBOR announced a delay in the phase out of a majority of the U.S. dollar LIBOR publications until June 30, 2023, with the remainder of LIBOR publications to still end at the end of 2021.

18   CALAMOS GLOBAL DYNAMIC INCOME FUND ANNUAL REPORT

There remains uncertainty regarding the future utilization of LIBOR and the nature of any replacement rate. As such, the potential effect of a transition away from LIBOR on the Fund or the financial instruments in which the Fund invests cannot yet be determined.

High Yield Securities Risk. The Fund may invest in high yield securities of any rating. Investment in high yield securities involves substantial risk of loss. Below investment grade non-convertible debt securities or comparable unrated securities are commonly referred to as “junk bonds” and are considered predominantly speculative with respect to the issuer’s ability to pay interest and principal and are susceptible to default or decline in market value due to adverse economic and business developments. The market values for high yield securities tend to be very volatile, and these securities are less liquid than investment grade debt securities. For these reasons, your investment in the Fund is subject to the following specific risks:

•increased price sensitivity to changing interest rates and to a deteriorating economic environment;

•greater risk of loss due to default or declining credit quality;

•adverse company specific events are more likely to render the issuer unable to make interest and/or principal payments; and

•if a negative perception of the high yield market develops, the price and liquidity of high yield securities may be depressed. This negative perception could last for a significant period of time.

Adverse changes in economic conditions are more likely to lead to a weakened capacity of a high yield issuer to make principal payments and interest payments than an investment grade issuer. The principal amount of high yield securities outstanding has proliferated since the inception of the Fund as an increasing number of issuers have used high yield securities for corporate financing. An economic downturn could severely affect the ability of highly leveraged issuers to service their debt obligations or to repay their obligations upon maturity. The Fund may incur additional expenses to the extent it is required to seek recovery upon a default in payment of principal or interest on its portfolio holdings. In certain circumstances, the Fund may be required to foreclose on an issuer’s assets and take possession of its property or operations. In such circumstances, the Fund would incur additional costs in disposing of such assets and potential liabilities from operating any business acquired.

The secondary market for high yield securities may not be as liquid as the secondary market for more highly rated securities, a factor which may have an adverse effect on the Fund’s ability to dispose of a particular security. There are fewer dealers in the market for high yield securities than for investment grade obligations. The prices quoted by different dealers may vary significantly and the spread between the bid and asked price is generally much larger than for higher quality instruments. Under adverse market or economic conditions, the secondary market for securities could contract further, independent of any specific adverse changes in the condition of a particular issuer, and these instruments may become illiquid. As a result, the Fund could find it more difficult to sell these securities or may be able to sell the securities only at prices lower than if such securities were widely traded. Prices realized upon the sale of such lower rated or unrated securities, under these circumstances, may be less than the prices used in calculating the Fund’s net asset value.

Synthetic Convertible Instruments Risk. The value of a synthetic convertible instrument may respond differently to market fluctuations than a convertible instrument because a synthetic convertible instrument is composed of two or more separate securities, each with its own market value. In addition, if the value of the underlying common stock or the level of the index involved in the convertible component falls below the exercise price of the warrant or option, the warrant or option may lose all value.

Geographic Concentration Risk. Investments in a particular country or geographic region may be particularly susceptible to political, diplomatic or economic conditions and regulatory requirements. To the extent the Fund concentrates its investments in a particular country, region or group of regions, the Fund may be more volatile than a more geographically diversified fund.

Sector Risk. To the extent the Fund invests a significant portion of its assets in a particular sector, a greater portion of the Fund’s performance may be affected by the general business and economic conditions affecting that sector. Each sector may share economic risk with the broader market, however there may be economic risks specific to each sector. As a result, returns from those sectors may trail returns from the overall stock market and it is possible that the Fund may underperform the broader market, or experience greater volatility.

American Depositary Receipts Risk. The stocks of most foreign companies that trade in the U.S. markets are traded as ADRs. U.S. depositary banks issue these stocks. Each ADR represents one or more shares of foreign stock or a fraction of a share. The price of an ADR corresponds to the price of the foreign stock in its home market, adjusted to the ratio of the ADRs to foreign company shares. Therefore while purchasing a security on a U.S. exchange, the risks inherently associated with foreign investing still apply to ADRs.

CALAMOS GLOBAL DYNAMIC INCOME FUND ANNUAL REPORT   19

Duration Risk. Duration measures the time-weighted expected cash flows of a fixed-income security, which can determine its sensitivity to changes in the general level of interest rates. The value of securities with longer durations tend to be more sensitive to interest rate changes than securities with shorter durations. The longer the Fund’s dollar-weighted average duration, the more its value can generally be expected to be sensitive to interest rate changes than a fund with a shorter dollar-weighted average duration. Duration differs from maturity in that it considers a security’s coupon payments in addition to the amount of time until the security matures. Various techniques may be used to shorten or lengthen the Fund’s duration. As the value of a security changes over time, so will its duration.

Inflation Risk. Inflation is the reduction in the purchasing power of money resulting from an increase in the price of goods and services. Inflation risk is the risk that the inflation adjusted or “real” value of an investment in preferred stock or debt securities or the income from that investment will be worth less in the future. As inflation occurs, the real value of the preferred stock or debt securities and the dividend payable to holders of preferred stock or interest payable to holders of debt securities declines.

Maturity Risk. Interest rate risk will generally affect the price of a fixed income security more if the security has a longer maturity. Fixed income securities with longer maturities will therefore be more volatile than other fixed income securities with shorter maturities. Conversely, fixed income securities with shorter maturities will be less volatile but generally provide lower potential returns than fixed income securities with longer maturities. The average maturity of the Fund’s investments will affect the volatility of the Fund’s share price.

Liquidity Risk. The Fund may invest without limit in securities that, at the time of investment, are illiquid (i.e., any investment that the Fund reasonably expects cannot be sold or disposed of in current market conditions in seven calendar days or less without the sale or disposition significantly changing the market value of the investment). The Fund may also invest without limit in Rule 144A Securities determined to be liquid. Calamos, under the supervision and oversight of the Board of Trustees, will determine whether Rule 144A Securities are illiquid (that is, not readily marketable). Illiquid securities may be difficult to dispose of at a fair price at the times when the Fund believes it is desirable to do so. Investment of the Fund’s assets in illiquid securities may restrict the Fund’s ability to take advantage of market opportunities. The market price of illiquid securities generally is more volatile than that of more liquid securities, which may adversely affect the price that the Fund pays for or recovers upon the sale of illiquid securities. Illiquid securities are also more difficult to value and may be fair valued by the Board of Trustees, in which case Calamos’ judgment may play a greater role in the valuation process. The risks associated with illiquid securities may be particularly acute in situations in which the Fund’s operations require cash and could result in the Fund borrowing to meet its short-term needs or incurring losses on the sale of illiquid securities.

Decline in Net Asset Value Risk. A material decline in our NAV may impair our ability to maintain required levels of asset coverage for any preferred securities or debt securities the Fund may issue in the future.

Counterparty and Settlement Risk. Trading options, futures contracts, swaps and other derivative financial instruments entails credit risk with respect to the counterparties. Such instruments when traded over the counter do not include the same protections as may apply to trading derivatives on organized exchanges. Substantial losses may arise from the insolvency, bankruptcy or default of a counterparty and risk of settlement default of parties with whom it trades securities. This risk may be heightened during volatile market conditions. Settlement mechanisms in emerging markets are generally less developed and reliable than those in more developed countries, thus increasing the risks. In the past, broker-dealers and other financial institutions have experienced extreme financial difficulty, sometimes resulting in bankruptcy of the institution. Although Calamos monitors the creditworthiness of the Fund’s counterparties, there can be no assurance that the Fund’s counterparties will not experience similar difficulties, possibly resulting in losses to the Fund. If a counterparty becomes bankrupt, or otherwise fails to perform its obligations under a derivative contract due to financial difficulties, the Fund may experience significant delays in obtaining any recovery under the derivative contract in a bankruptcy or other reorganization proceeding. The Fund may obtain only a limited recovery or may obtain no recovery in such circumstances. Material exposure to a single or small group of counterparties increases the Fund’s counterparty risk.

Portfolio Turnover Risk. The portfolio managers may actively and frequently trade securities or other instruments in the Fund’s portfolio to carry out its investment strategies. A high portfolio turnover rate increases transaction costs, which may increase the Fund’s expenses. Frequent and active trading may also cause adverse tax consequences for investors in the Fund due to an increase in short-term capital gains.

REIT Risk. Investing in real estate investment trusts (“REITs”) involves certain unique risks in addition to those risks associated with investing in the real estate industry in general. An equity REIT may be affected by changes in the value of the underlying properties owned by the REIT. A mortgage REIT may be affected by changes in interest rates and the ability of the issuers of its portfolio

20   CALAMOS GLOBAL DYNAMIC INCOME FUND ANNUAL REPORT

mortgages to repay their obligations. REITs are dependent upon the skills of their managers and are not diversified. REITs are generally dependent upon maintaining cash flows to repay borrowings and to make distributions to shareholders and are subject to the risk of default by lessees or borrowers. REITs whose underlying assets are concentrated in properties used by a particular industry, such as health care, are also subject to risks associated with such industry.

REITs (especially mortgage REITs) are also subject to interest rate risks. When interest rates decline, the value of a REIT’s investment in fixed rate obligations can be expected to rise. Conversely, when interest rates rise, the value of a REIT’s investment in fixed rate obligations can be expected to decline. If the REIT invests in adjustable rate mortgage loans the interest rates on which are reset periodically, yields on a REIT’s investments in such loans will gradually align themselves to reflect changes in market interest rates. This causes the value of such investments to fluctuate less dramatically in response to interest rate fluctuations than would investments in fixed rate obligations.

REITs may have limited financial resources, may utilize significant amounts of leverage, may trade less frequently and in a limited volume and may be subject to more abrupt or erratic price movements than larger company securities. Historically, REITs have been more volatile in price than the larger capitalization stocks included in Standard & Poor’s 500 Stock Index.

Other Investment Companies (including ETFs) Risk. Investments in the securities of other investment companies, including ETFs, may involve duplication of advisory fees and certain other expenses. By investing in another investment company or ETF, the Fund becomes a shareholder thereof. As a result, Fund shareholders indirectly bear the Fund’s proportionate share of the fees and expenses indirectly paid by shareholders of the other investment company or ETF, in addition to the fees and expenses Fund shareholders bear in connection with the Fund’s own operations. If the investment company or ETF fails to achieve its investment objective, the value of the Fund’s investment will decline, adversely affecting the Fund’s performance. In addition, closed-end investment company and ETF shares potentially may trade at a discount or a premium and are subject to brokerage and other trading costs, which could result in greater expenses to the Fund. In addition, the Fund may engage in short sales of the securities of other investment companies. When the Fund shorts securities of another investment company, it borrows shares of that investment company which it then sells. The Fund closes out a short sale by purchasing the security that it has sold short and returning that security to the entity that lent the security.

Cash Holdings Risk. To the extent the Fund holds cash positions, the Fund risks achieving lower returns and potential lost opportunities to participate in market appreciation which could negatively impact the Fund’s performance and ability to achieve its investment objective.

Cybersecurity Risk. Investment companies, such as the Fund, and their service providers are exposed to operational and information security risks resulting from cyberattacks, which may result in financial losses to a fund and its shareholders. Cyber-attacks include, among other behaviors, stealing or corrupting data maintained online or digitally, denial of service attacks on websites, “ransomware” that renders systems inoperable until ransom is paid, the unauthorized release of confidential information, or various other forms of cybersecurity breaches. Cyber-attacks affecting the Fund or the Adviser, custodian, transfer agent, distributor, administrator, intermediaries, trading counterparties, and other third-party service providers may adversely impact the Fund or the companies in which the Fund invests, causing the Fund’s investments to lose value or to prevent a shareholder redemption or purchase from clearing in a timely manner.

Forward Currency Exchange Contracts Risk. Forward contracts are contractual agreements to purchase or sell a specified currency at a specified future date (or within a specified time period) at a price set at the time of the contract. The Fund may not fully benefit from, or may lose money on, forward currency exchange transactions if changes in currency exchange rates do not occur as anticipated or do not correspond accurately to changes in the value of the Fund’s holdings.

Futures and Forward Contracts Risk. Futures contracts provide for the future sale by one party and purchase by another of a specific asset at a specific time and price (with or without delivery required). Futures contracts are standardized contracts traded on a recognized exchange. An option on a futures contract gives the purchaser the right, in exchange for a premium, to assume a position in a futures contract at a specified exercise price during the term of the option. Futures and forward contracts are subject to counterparty risk, meaning that the party who issues the derivatives (the clearinghouse or the broker holding the Fund’s position for a futures contract or the counterparty for a forward contract) may experience a significant credit event and may be unwilling or unable to make timely settlement payments or otherwise honor its obligations.

Interest Rate Transactions Risk. The Fund may enter into an interest rate swap, cap or floor transaction to attempt to protect itself from increasing dividend or interest expenses on its leverage resulting from increasing short-term interest rates and to hedge its portfolio securities. A decline in interest rates may result in a decline in the value of the swap or cap, which may result in a decline in the NAV of the Fund.

CALAMOS GLOBAL DYNAMIC INCOME FUND ANNUAL REPORT   21

Depending on the state of interest rates in general, the Fund’s use of interest rate swap or cap transactions could enhance or harm the overall performance of the common shares. To the extent there is a decline in interest rates, the value of the interest rate swap or cap could decline, and could result in a decline in the NAV of the common shares. In addition, if the counterparty to an interest rate swap or cap defaults, the Fund would not be able to use the anticipated net receipts under the swap or cap to offset the dividend or interest payments on the Fund’s leverage.

Depending on whether the Fund would be entitled to receive net payments from the counterparty on the swap or cap, which in turn would depend on the general state of short-term interest rates at that point in time, such a default could negatively impact the performance of the common shares. In addition, at the time an interest rate swap or cap transaction reaches its scheduled termination date, there is a risk that the Fund would not be able to obtain a replacement transaction or that the terms of the replacement would not be as favorable as on the expiring transaction. If either of these events occurs, it could have a negative impact on the performance of the common shares.

If the Fund fails to maintain a required 200% asset coverage of the liquidation value of any outstanding preferred shares or if the Fund loses its rating on its preferred shares or fails to maintain other covenants with respect to the preferred shares, the Fund may be required to redeem some or all of the preferred shares. Similarly, the Fund could be required to prepay the principal amount of any debt securities or other borrowings. Such redemption or prepayment would likely result in the Fund seeking to terminate early all or a portion of any swap or cap transaction. Early termination of a swap could result in a termination payment by or to the Fund. Early termination of a cap could result in a termination payment to the Fund. The Fund intends to segregate with its custodian cash or liquid securities having a value at least equal to the Fund’s net payment obligations under any swap transaction, marked-to-market daily.

Currently, certain categories of interest rate swaps are subject to mandatory clearing, and more are expected to be cleared in the future. The counterparty risk for cleared derivatives is generally lower than for uncleared OTC derivative transactions because generally a clearing organization becomes substituted for each counterparty to a cleared derivative contract and, in effect, guarantees the parties’ performance under the contract as each party to a trade looks only to the clearing house for performance of financial obligations. However, there can be no assurance that a clearing house, or its members, will satisfy the clearing house’s obligations to the Fund.

Market Impact Risk. The sale of our common shares (or the perception that such sales may occur) may have an adverse effect on prices in the secondary market for our common shares. An increase in the number of common shares available may put downward pressure on the market price for our common shares. These sales also might make it more difficult for us to sell additional equity securities in the future at a time and price the Fund deems appropriate.

Non-U.S. Government Obligation Risk. An investment in debt obligations of non-U.S. governments and their political subdivisions involves special risks that are not present in corporate debt obligations. The non-U.S. issuer of the sovereign debt or the non-U.S. governmental authorities that control the repayment of the debt may be unable or unwilling to repay principal or interest when due, and the Fund may have limited recourse in the event of a default. During periods of economic uncertainty, the market prices of sovereign debt may be more volatile than prices of debt obligations of U.S. issuers.

U.S. Government Security Risk. Some securities issued by U.S. Government agencies or government sponsored enterprises are not backed by the full faith and credit of the U.S. and may only be supported by the right of the agency or enterprise to borrow from the U.S. Treasury. There can be no assurance that the U.S. Government will always provide financial support to those agencies or enterprises.

Rule 144A Securities Risk. The Fund may invest in securities that are issued and sold through transactions under Rule 144A of the Securities Act of 1933. Under the supervision and oversight of the Board of Trustees, Calamos will determine whether Rule 144A Securities are illiquid. If qualified institutional buyers are unwilling to purchase these Rule 144A Securities, the percentage of the Fund’s assets invested in illiquid securities would increase. Typically, the Fund purchases Rule 144A Securities only if the Fund’s adviser has determined them to be liquid. If any Rule 144A Security held by the Fund should become illiquid, the value of the security may be reduced and a sale of the security may be more difficult.

Tax Risk. The Fund may invest in certain securities, such as certain convertible securities and high yield securities, for which the federal income tax treatment may not be clear or may be subject to re-characterization by the Internal Revenue Service (“IRS”). It could be more difficult for the Fund to comply with the federal income tax requirements applicable to regulated investment companies if the tax characterization of the Fund’s investments is not clear or if the tax treatment of the income from such investments was successfully challenged by the IRS. In addition, the tax treatment of the Fund may be affected by future interpretations of the Internal Revenue Code of 1986, as amended and changes in the tax laws and regulations, all of which may apply with retroactive effect.

22   CALAMOS GLOBAL DYNAMIC INCOME FUND ANNUAL REPORT

Contingent Liabilities Risk. Entering into derivative contracts in order to pursue the Fund’s various hedging strategies could require the Fund to fund cash payments in the future under certain circumstances, including an event of default or other early termination event, or the decision by a counterparty to request margin in the form of securities or other forms of collateral under the terms of the derivative contract or applicable laws. The amounts due with respect to a derivative contract would generally be equal to the unrealized loss of the open positions with the respective counterparty and could also include other fees and charges. These payments are contingent liabilities and therefore may not appear on the Fund’s balance sheet. The Fund’s ability to fund these contingent liabilities will depend on the liquidity of the Fund’s assets and access to capital at the time, and the need to fund these contingent liabilities could adversely impact our financial condition.

Antitakeover Provisions. The Fund’s Agreement and Declaration of Trust and By-Laws include provisions that could limit the ability of other entities or persons to acquire control of the Fund or to change the composition of its Board of Trustees. Such provisions could limit the ability of shareholders to sell their shares at a premium over prevailing market prices by discouraging a third party from seeking to obtain control of the Fund. These provisions include staggered terms of office for the Trustees, advance notice requirements for shareholder proposals, and super-majority voting requirements for certain transactions with affiliates, converting the Fund to an open-end investment company or a merger, asset sale or similar transaction. Holders of preferred shares have voting rights in addition to and separate from the voting rights of common shareholders with respect to certain of these matters. Holders of any preferred shares, voting separately as a single class, have the right to elect at least two Trustees at all times. The holders of preferred shares or debt, if any, on the one hand, and the holders of the common shares, on the other, may have interests that conflict with each other in certain situations, including conflicts that relate to the fees and expenses of the Fund.

Loan Risk.  The Fund may invest in loans which may not be (i) rated at the time of investment, (ii) registered with the SEC or (iii) listed on a securities exchange. There may not be as much public information available regarding these loans as is available for other Fund investments, such as exchange-listed securities. As well, there may not be an active trading market for some loans, meaning they may be illiquid and more difficult to value than other more liquid securities. Settlement periods for loans are longer than for exchange-traded securities, typically ranging between 1 and 3 weeks, and in some cases much longer. There is no central clearinghouse for loan trades, and the loan market has not established enforceable settlement standards or remedies for failure to settle. Because the interest rates of floating-rate loans in which the Fund may invest may reset frequently, if market interest rates fall, the loans’ interest rates will be reset to lower levels, potentially reducing the Fund’s income. Because the adviser may wish to invest in the publicly-traded securities of an obligor, the Fund may not have access to material non-public information regarding the obligor to which other investors have access.

“Covenant-Lite” Loans Risk. Some of the loans in which the Fund may invest may be “covenant-lite” loans, which means the loans contain fewer or no maintenance covenants than other loans and do not include terms which allow the lender to monitor the performance of the borrower and declare a default if certain criteria are breached. The Fund may experience delays in enforcing its rights on its holdings of covenant-lite loans.

Short Selling Risk. The Fund will engage in short sales for investment and risk management purposes, including when the Adviser believes an investment will underperform due to a greater sensitivity to earnings growth of the issuer, default risk or interest rates. In times of unusual or adverse market, economic, regulatory or political conditions, the Fund may not be able, fully or partially, to implement its short selling strategy. Periods of unusual or adverse market, economic, regulatory or political conditions may exist for extended periods of time.

Short sales are transactions in which the Fund sells a security or other instrument that it does not own but can borrow in the market. Short selling allows the Fund to profit from a decline in market price to the extent such decline exceeds the transaction costs and the costs of borrowing the securities and to obtain a low cost means of financing long investments that the Adviser believes are attractive. If a security sold short increases in price, the Fund may have to cover its short position at a higher price than the short sale price, resulting in a loss. The Fund will have substantial short positions and must borrow those securities to make delivery to the buyer under the short sale transaction. The Fund may not be able to borrow a security that it needs to deliver or it may not be able to close out a short position at an acceptable price and may have to sell related long positions earlier than it had expected. Thus, the Fund may not be able to successfully implement its short sale strategy due to limited availability of desired securities or for other reasons. Also, there is the risk that the counterparty to a short sale may fail to honor its contractual terms, causing a loss to the Fund.

Generally, the Fund will have to pay a fee or premium to borrow securities and will be obligated to repay the lender of the security any dividends or interest that accrues on the security during the term of the loan. The amount of any gain from a short sale will be decreased, and the amount of any loss increased, by the amount of such fee, premium, dividends, interest or expense the Fund pays in connection with the short sale.

CALAMOS GLOBAL DYNAMIC INCOME FUND ANNUAL REPORT   23

Until the Fund replaces a borrowed security, it may be required to maintain a segregated account of cash or liquid assets with a broker or custodian to cover the Fund’s short position. Generally, securities held in a segregated account cannot be sold unless they are replaced with other liquid assets. The Fund’s ability to access the pledged collateral may also be impaired in the event the broker becomes bankrupt, insolvent or otherwise fails to comply with the terms of the contract. In such instances the Fund may not be able to substitute or sell the pledged collateral and may experience significant delays in obtaining any recovery in a bankruptcy or other reorganization proceeding. The Fund may obtain only a limited recovery or may obtain no recovery in these circumstances. Additionally, the Fund must maintain sufficient liquid assets (less any additional collateral pledged to the broker), marked-to-market daily, to cover the borrowed securities obligations. This may limit the Fund’s investment flexibility, as well as its ability to meet other current obligations.

Because losses on short sales arise from increases in the value of the security sold short, such losses are theoretically unlimited. By contrast, a loss on a long position arises from decreases in the value of the security and is limited by the fact that a security’s value cannot decrease below zero. The Adviser’s use of short sales in combination with long positions in the Fund’s portfolio in an attempt to improve performance or reduce overall portfolio risk may not be successful and may result in greater losses or lower positive returns than if the Fund held only long positions. It is possible that the Fund’s long securities positions will decline in value at the same time that the value of its short securities positions increase, thereby increasing potential losses to the Fund. In addition, the Fund’s short selling strategies will limit its ability to fully benefit from increases in the fixed-income markets.

By investing the proceeds received from selling securities short, the Fund could be deemed to be employing a form of leverage, which creates special risks. The use of leverage may increase the Fund’s exposure to long securities positions and make any change in the Fund’s NAV greater than it would be without the use of leverage. This could result in increased volatility of returns. There is no guarantee that any leveraging strategy the Fund employs will be successful during any period in which it is employed.

Diminished Voting Power and Excess Cash Risk. The voting power of current shareholders will be diluted to the extent that such shareholders do not purchase shares in any future common share offerings or do not purchase sufficient shares to maintain their percentage interest. In addition, if the Fund is unable to invest the proceeds of such offering as intended, its per share distribution may decrease (or may consist of return of capital) and the Fund may not participate in market advances to the same extent as if such proceeds were fully invested as planned.

Senior Leverage Risk. Our preferred shares will be junior in liquidation and with respect to distribution rights to our debt securities and any other borrowings. Senior securities representing indebtedness may constitute a substantial lien and burden on preferred shares by reason of their prior claim against our income and against our net assets in liquidation. The Fund may not be permitted to declare dividends or other distributions with respect to any series of our preferred shares unless at such time the Fund meets applicable asset coverage requirements and the payment of principal or interest is not in default with respect to any borrowings.

Ratings and Asset Coverage Risk. To the extent that senior securities are rated, a rating does not eliminate or necessarily mitigate the risks of investing in our senior securities, and a rating may not fully or accurately reflect all of the credit and market risks associated with that senior security. A rating agency could downgrade the rating of our preferred shares or debt securities, which may make such securities less liquid in the secondary market, though probably with higher resulting interest rates. If a rating agency downgrades the rating assigned to a senior security, the Fund may alter its portfolio or redeem the senior security. The Fund may voluntarily redeem senior securities under certain circumstances.

IMPORTANT UPDATES ABOUT THE FUND

Change to Ratings Agency for the Mandatory Redeemable Preferred Shares (MRPS)

As of December 17, 2020, Kroll Bond Rating Agency LLC (“Kroll”) replaced Fitch Ratings, Inc. (“Fitch”) as the rating agency for the MRPS. The MRPS have been assigned a rating of ‘AA-’ by Kroll.