Calamos Calamos Investment Trust [CIT] Prospectus [Funds] 033-19228 03-01-2023 ED [AUX]

Family of Funds

   

CLASS A

 

CLASS C

 

CLASS I

 

CLASS R6

 

Alternative

 

Calamos Market Neutral Income Fund

 

CVSIX

 

CVSCX

 

CMNIX

 

CVSOX

 

Calamos Hedged Equity Fund

 

CAHEX

 

CCHEX

 

CIHEX

     

Calamos Phineus Long/Short Fund

  CPLSX   CPCLX   CPLIX      

Convertible

 

Calamos Convertible Fund

 

CCVIX

 

CCVCX

 

CICVX

     

Calamos Global Convertible Fund

 

CAGCX

 

CCGCX

 

CXGCX

     

U.S. Equity

 

Calamos Timpani Small Cap Growth Fund

 

CTASX

 

CTCSX

 

CTSIX

 

CTSOX

 

Calamos Timpani SMID Growth Fund

 

CTAGX

     

CTIGX

 

CTOGX

 

Calamos Growth Fund

 

CVGRX

 

CVGCX

 

CGRIX

     

Calamos Growth and Income Fund

 

CVTRX

 

CVTCX

 

CGIIX

 

CGIOX

 

Calamos Dividend Growth Fund

  CADVX  

CCDVX

 

CIDVX

     

Calamos Select Fund

 

CVAAX

 

CVACX

 

CVAIX

     

Global Equity

 

Calamos International Growth Fund

 

CIGRX

 

CIGCX

 

CIGIX

 

CIGOX

 

Calamos Evolving World Growth Fund

 

CNWGX

 

CNWDX

 

CNWIX

     

Calamos Global Equity Fund

 

CAGEX

 

CCGEX

 

CIGEX

 

CGEOX

 

Calamos Global Opportunities Fund

 

CVLOX

 

CVLCX

 

CGCIX

     

Calamos International Small Cap Growth Fund

 

CAISX

 

CCISX

 

CSGIX

 

CISOX

 

Fixed Income

 

Calamos Total Return Bond Fund

 

CTRAX

 

CTRCX

 

CTRIX

     

Calamos High Income Opportunities Fund

 

CHYDX

 

CCHYX

 

CIHYX

     

Calamos Short-Term Bond Fund

 

CSTBX

     

CSTIX

     

Prospectus March 1, 2023

The Securities and Exchange Commission has not approved or disapproved these securities or determined whether this prospectus is truthful or complete. Any representation to the contrary is a criminal offense.


 

Table of Contents

The Funds

 

Alternative

 
Calamos Market Neutral Income
Fund
   

1

   

Calamos Hedged Equity Fund

   

8

   

Calamos Phineus Long/Short Fund

   

15

   

Convertible

 

Calamos Convertible Fund

   

22

   

Calamos Global Convertible Fund

   

28

   

U.S. Equity

 
Calamos Timpani Small Cap Growth
Fund
   

35

   
Calamos Timpani SMID Growth
Fund
   

40

   

Calamos Growth Fund

   

45

   

Calamos Growth and Income Fund

   

50

   

Calamos Dividend Growth Fund

   

56

   

Calamos Select Fund

   

62

   

Global Equity

 
Calamos International Growth
Fund
   

67

   
Calamos Evolving World Growth
Fund
   

72

   

Calamos Global Equity Fund

   

78

   
Calamos Global Opportunities
Fund
   

83

   
Calamos International Small Cap
Growth Fund
   

89

   

Fixed Income

 

Calamos Total Return Bond Fund

   

94

   
Calamos High Income Opportunities
Fund
   

101

   

Calamos Short-Term Bond Fund

   

108

   
Other Important Information
Regarding Fund Shares
   

115

   
Additional Information About
Investment Strategies and Related
Risks
   

117

   

Fund Facts

   

131

   

Who manages the Funds?

   

131

   
What classes of shares do the Funds
offer?
   

138

   

How can I buy shares?

   

148

   

How can I sell (redeem) shares?

   

151

   

Transaction information

   

156

   

Distributions and taxes

   

161

   

Other Information

   

163

   

Financial Highlights

   

166

   

Appendix

         

For More Information

   

back cover

   


Calamos Market Neutral Income Fund

Investment Objective

Calamos Market Neutral Income Fund's investment objective is high current income consistent with stability of principal.

Fees and Expenses of the Fund

The following table describes the fees and expenses that you may pay if you buy, hold and sell shares of the Fund. Investors may pay other fees, such as brokerage commissions and/or other forms of compensation to a financial intermediary, which are not reflected in the tables or the examples below. You may qualify for sales charge discounts on purchases of Class A shares if you and your family invest, or agree to invest in the future, at least $100,000 in Calamos Funds. More information about these and other discounts is available from your financial professional and under "Fund Facts — What classes of shares do the Funds offer?" on page 138 of the Fund's prospectus, in the Appendix to this prospectus and "Share Classes and Pricing of Shares" on page 66 of the Fund's statement of additional information.

Shareholder Fees (fees paid directly from your investment):

   

CLASS A

 

CLASS C

 

CLASS I

 

CLASS R6

 
Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of
offering price)
   

2.75

%

   

None

     

None

     

None

   
Maximum Deferred Sales Charge (Load) (as a percentage of the lesser of the
redemption price or offering price)
   

None

     

1.00

%

   

None

     

None

   

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment):

   

CLASS A

 

CLASS C

 

CLASS I

 

CLASS R6

 

Management Fees

   

0.65

%

   

0.65

%

   

0.65

%

   

0.65

%

 

Distribution and/or Service Fees (12b-1)

   

0.25

%

   

1.00

%

   

None

     

None

   

Dividend Expense on Short Positions

   

0.15

%

   

0.15

%

   

0.15

%

   

0.17

%

 

Other Expenses

   

0.12

%

   

0.12

%

   

0.12

%

   

0.05

%

 

Acquired Fund Fees and Expenses1

   

0.01

%

   

0.01

%

   

0.01

%

   

0.01

%

 

Total Annual Fund Operating Expenses

   

1.18

%

   

1.93

%

   

0.93

%

   

0.88

%

 

1  "Acquired Fund Fees and Expenses" include certain expenses incurred in connection with the Fund's investment in various money market funds, affiliated mutual funds, and ETFs.

Example

This example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds. The example assumes that you invest $10,000 in the Fund for the time periods indicated and then either redeem or do not redeem your shares at the end of the reflected time periods. The example also assumes that your investment has a 5% return each year, that all dividends and capital gain distributions are reinvested, that you pay a maximum initial or contingent deferred sales charge and that the Fund's operating expenses remain the same. Although your actual performance and costs may be higher or lower, based on these assumptions, your costs would be:

You would pay the following expenses if you redeemed your shares at the end of the period:

   

One Year

 

Three Years

 

Five Years

 

Ten Years

 

Class A

   

392

     

639

     

906

     

1,667

   

Class C

   

296

     

606

     

1,042

     

2,254

   

Class I

   

95

     

296

     

515

     

1,143

   

Class R6

   

90

     

281

     

488

     

1,084

   

PROSPECTUS | March 1, 2023
1


Calamos Market Neutral Income Fund

You would pay the following expenses if you did not redeem your shares:

   

One Year

 

Three Years

 

Five Years

 

Ten Years

 

Class A

   

392

     

639

     

906

     

1,667

   

Class C

   

196

     

606

     

1,042

     

2,254

   

Class I

   

95

     

296

     

515

     

1,143

   

Class R6

   

90

     

281

     

488

     

1,084

   

Portfolio Turnover

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when Fund shares are held in a taxable account. These costs, which are not reflected in the annual fund operating expenses or in the example, affect the Fund's performance. During the most recent fiscal year, the Fund's portfolio turnover rate was 41% of the average value of its portfolio.

Principal Investment Strategies

The Fund's investment strategy can be characterized as "market neutral" because it seeks to achieve maximum current income while maintaining a low correlation to the fluctuations of the U.S. equity market as a whole. The Fund (i) invests in equities, (ii) invests in convertible securities (including synthetic convertible securities) of U.S. companies without regard to market capitalization, and (iii) employs short selling and enters into total return swaps to enhance income and hedge against market risk. The convertible securities in which the Fund invests may be either debt securities or preferred stocks that can be exchanged for common stock. The average term to maturity of the convertible securities purchased by the Fund will typically range from two to ten years.

A synthetic convertible instrument is a financial instrument (or two or more securities held in tandem) that is designed to simulate the economic characteristics of a convertible security through the combined features of a debt instrument and a security providing an option on an equity security. The Fund may establish a synthetic convertible instrument by combining fixed-income securities (which may be either convertible or non-convertible) with the right to acquire equity securities. In establishing a synthetic instrument, the Fund may combine a basket of fixed-income securities with a basket of warrants or options that together produce economic characteristics similar to a convertible security. Within each basket of fixed-income securities and warrants or options, different companies may issue the fixed-income and convertible components, which may be purchased separately and at different times.

The Fund may seek to generate income from option premiums by writing (selling) options. This would include the use of both call and put options. The Fund may write call options (i) on a portion of the equity securities (including securities that are convertible into equity securities) in the Fund's portfolio and (ii) on broad-based securities indexes (such as the S&P 500 or MSCI EAFE) or ETFs (exchange traded funds).

In addition, to seek to offset some of the risk of a potential decline in value of certain long positions, the Fund may also purchase put options on individual securities, broad-based securities indexes (such as the S&P 500), or ETFs.

The Fund may invest without limit in high yield fixed-income securities (often referred to as "junk bonds"). The Fund may invest up to 10% of its total assets in stock, rights, warrants, and other securities of special purpose acquisition companies or similar special purpose entities (collectively, "SPACs"). In addition, the Fund may obtain certain private rights and other interests issued by a SPAC (commonly referred to as "founder shares"), which may be subject to forfeiture or expire worthless and which generally have more limited liquidity than SPAC shares issued in an initial public offering. In addition, the Fund may engage in active and frequent trading of portfolio securities. The Fund may also invest in ETFs. The Fund's investment adviser seeks to lower the risks of investing in stocks by using a "top-down approach" of diversification by company, industry, sector, country and currency and focusing on macro-level investment themes.

CALAMOS FAMILY OF FUNDS
2


Calamos Market Neutral Income Fund

Principal Risks

An investment in the Fund is subject to risks, and you could lose money on your investment in the Fund. There can be no assurance that the Fund will achieve its investment objective. The risks associated with an investment in the Fund can increase during times of significant market volatility. Your investment in the Fund is not a deposit in a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency. The principal risks are presented in alphabetical order to facilitate finding particular risks and comparing them with other funds. Each risk summarized below is considered a "principal risk" of investing in the Fund, regardless of the order in which it appears. The principal risks of investing in the Fund include:

•  Convertible Hedging Risk — If the market price of the underlying common stock increases above the conversion price on a convertible security, the price of the convertible security will increase. The Fund's increased liability on any outstanding short position would, in whole or in part, reduce this gain.

•  Convertible Securities Risk — The value of a convertible security is influenced by changes in interest rates, with investment value declining as interest rates increase and increasing as interest rates decline. The credit standing of the issuer and other factors also may have an effect on the convertible security's investment value.

•  Covered Call Writing Risk — As the writer of a covered call option on a security, the Fund foregoes, during the option's life, the opportunity to profit from increases in the market value of the security covering the call option above the sum of the premium and the exercise price of the call.

•  Debt Securities Risk — Debt securities are subject to various risks, including interest rate risk, credit risk and default risk.

•  Interest Rate Risk — The value of debt securities generally decreases in periods when interest rates are rising. In addition, interest rate changes typically have a greater effect on prices of longer-term debt securities than shorter term debt securities. Recent fixed-income market events, including increases in volatility and interest rates, may expose the Fund to heightened interest rate risk and volatility.

•  Credit Risk — A debt security could deteriorate in quality to such an extent that its rating is downgraded or its market value declines relative to comparable securities. Changes in actual or perceived creditworthiness may occur quickly. If the Fund holds securities that have been downgraded, or that default on payment, the Fund's performance could be negatively affected.

•  Default Risk — A company that issues a debt security may be unable to fulfill its obligation to repay principal and interest. The lower a bond is rated, the greater its default risk. To the extent the Fund holds securities that have been downgraded, or that default on payment, its performance could be negatively affected.

•  Derivatives Risk — Derivatives are instruments, such as futures and forward foreign currency contracts, whose value is derived from that of other assets, rates or indices. The use of derivatives for non-hedging purposes may be considered more speculative than other types of investments. Derivatives can be used for hedging (attempting to reduce risk by offsetting one investment position with another) or non-hedging purposes. Hedging with derivatives may increase expenses, and there is no guarantee that a hedging strategy will work. While hedging can reduce or eliminate losses, it can also reduce or eliminate gains. In addition, derivative instruments are subject to counterparty risk, meaning that the party with whom the Fund enters into a derivative transaction may experience a significant credit event and/or may be unwilling or unable to make timely settlement payments or otherwise honor its obligations. Changes in the value of a derivative may not correlate perfectly with the underlying asset, rate or index, and the Fund could lose more than the principal amount invested.

•  Equity Securities Risk — The securities markets are volatile, and the market prices of the Fund's securities may decline generally. The price of equity securities fluctuates based on changes in a company's financial condition and overall market and economic conditions. If the market prices of the securities owned by the Fund (i.e., the Fund's long position) fall, the value of your investment in the Fund will decline.

•  Foreign Securities Risk — Risks associated with investing in foreign securities include fluctuations in the exchange rates of foreign currencies that may affect the U.S. dollar value of a security, the possibility of substantial price volatility as a result of political and economic instability in the foreign country, less public information about issuers of securities,

PROSPECTUS | March 1, 2023
3


Calamos Market Neutral Income Fund

different securities regulation, different accounting, auditing and financial reporting standards and less liquidity than in U.S. markets.

•  High Yield Risk — High yield securities and unrated securities of similar credit quality (commonly known as "junk bonds") are subject to greater levels of credit and liquidity risks. High yield securities are considered primarily speculative with respect to the issuer's continuing ability to make principal and interest payments.

•  Liquidity Risk — Liquidity risk exists when particular investments are difficult to purchase or sell. The Fund's investments in illiquid securities may reduce the returns of the Fund because it may be unable to sell the illiquid securities at an advantageous time or price.

•  Options Risk — The Fund's ability to close out its position as a purchaser or seller of an over-the-counter or exchange- listed put or call option is dependent, in part, upon the liquidity of the options market. There are significant differences between the securities and options markets that could result in an imperfect correlation among these markets, causing a given transaction not to achieve its objectives. The Fund's ability to utilize options successfully will depend on the ability of the Fund's investment adviser to predict pertinent market movements, which cannot be assured.

•  Other Investment Companies (including ETFs) Risk — The Fund may invest in the securities of other investment companies to the extent that such investments are consistent with the Fund's investment objective and the policies are permissible under the 1940 Act. Investments in the securities of other investment companies, including ETFs, may involve duplication of advisory fees and certain other expenses. Additionally, 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.

•  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.

•  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.

•  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 of its board of trustees, the Fund 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.

•  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.

•  Securities Lending Risk — The Fund may lend its portfolio securities to broker-dealers and banks in order to generate additional income for the Fund. Any such loan must be continuously secured by collateral in cash or cash equivalents maintained on a current basis in an amount at least equal to the market value of the securities loaned by the Fund. In the event of bankruptcy or other default of a borrower of portfolio securities, the Fund could experience both delays in liquidating the loan collateral or recovering the loaned securities and losses, including (a) possible decline in the value of

CALAMOS FAMILY OF FUNDS
4


Calamos Market Neutral Income Fund

the collateral or in the value of the securities loaned during the period while the Fund seeks to enforce its rights thereto, (b) possible subnormal levels of income and lack of access to income during this period, and (c) expenses of enforcing its rights. In an effort to reduce these risks, the Fund's securities lending agent monitors, and reports to Calamos Advisors on, the creditworthiness of the firms to which a Fund lends securities. The Fund may also experience losses as a result of a diminution in value of its cash collateral investments.

•  Short Sale Risk — The Fund may incur a loss (without limit) as a result of a short sale if the market value of the borrowed security (i.e., the Fund's short position) increases between the date of the short sale and the date the Fund replaces the security. The Fund may be unable to repurchase the borrowed security at a particular time or at an acceptable price.

•  Small and Mid-Sized Company Risk — Small and mid-sized company stocks have historically been subject to greater investment risk than large company stocks. The prices of small and mid-sized company stocks tend to be more volatile than prices of large company stocks.

•  Special Purpose Acquisition Companies Risk — The Fund may invest in special purpose acquisition companies ("SPACs") or similar special purpose entities. Because SPACs and similar entities have no operating history or ongoing business other than seeking acquisitions, the value of their securities is particularly dependent on the ability of the entity's management to identify and complete a profitable acquisition. Some SPACs may pursue acquisitions only within certain industries or regions, which may increase the volatility of their prices. A SPAC will not generate any revenues until, at the earliest, after the consummation of a transaction. An attractive acquisition or merger target may not be identified at all, in which case the SPAC will be required to return any remaining monies to shareholders, and the Fund may be subject to opportunity costs to the extent that alternative investments would have produced higher return. While a SPAC is seeking a transaction target, its stock may be thinly traded and/or illiquid. The proceeds of a SPAC IPO that are placed in trust are subject to risks, including the risk of insolvency of the custodian of the funds, fraud by the trustee, interest rate risk and credit and liquidity risk relating to the securities and money market funds in which the proceeds are invested. The private rights or other interests issued by a SPAC that the Fund may obtain generally have more limited liquidity than SPAC shares issued in an IPO and may be subject to forfeiture or expire worthless.

•  Synthetic Convertible Instruments Risk — The value of a synthetic convertible instrument will respond differently to market fluctuations than a convertible security 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.

•  Tax Risk — The federal income tax treatment of convertible securities or other securities in which the Fund may invest may not be clear or may be subject to recharacterization by the Internal Revenue Service. It could be more difficult to comply with the tax requirements applicable to regulated investment companies if the tax characterization of investments or the tax treatment of the income from such investments were successfully challenged by the Internal Revenue Service. Any such failure to comply with the rules applicable to regulated investment companies could cause the Fund to fail to qualify as such.

•  Total Return Swap Risk — A total return swap is a contract in which one party agrees to make periodic payments to another party based on the change in market value of the assets underlying the contract, which may include a specified security, basket of securities, or securities indices during the specified period, in return for periodic payments based on a fixed or variable interest rate or the total return from other underlying assets. Total return swap agreements may be used to obtain exposure to a security or market without owning or taking physical custody of such security or investing directly in such market. Total return swap agreements may effectively add leverage to a fund's portfolio because, in addition to its total net assets, the fund would be subject to investment exposure on the notional amount of the swap. The primary risks associated with total return swaps are credit risk (if the counterparty fails to meet its obligations) and market risk (if there is no liquid market for the agreement or unfavorable changes occur to the underlying asset).

PROSPECTUS | March 1, 2023
5


Calamos Market Neutral Income Fund

Fund Performance

The following bar chart and table indicate the risks of investing in the Fund by showing changes in the Fund's performance from calendar year to calendar year and how the Fund's average annual total returns compare with those of a broad measure of market performance. All returns include the reinvestment of dividends and distributions. As always, please note that the Fund's past performance (before and after taxes) cannot predict how it will perform in the future. Updated performance information is available at no cost by visiting www.calamos.com or by calling 800.582.6959.

CLASS I* ANNUAL TOTAL RETURN FOR YEARS ENDED 12.31

Highest Quarterly Return:

   

5.08

% (6.30.2020)

 

Lowest Quarterly Return:

   

-5.71

% (6.30.2022)

 

*  Annual returns for Class I are provided because Class I shares represent the largest percentage of assets in the Calamos Family of Funds.

Average Annual Total Returns as of 12.31.22

The following table shows how the Fund's average annual performance (before and after taxes) for the one-, five- and ten-year periods ended December 31, 2022 and since the Fund's inception compared with broad measures of market performance. "Since Inception" returns shown for each index are returns since the inception of the Fund's Class A shares, or since the nearest subsequent month end when comparative index data is available only for full monthly periods. The after-tax returns show the impact of assumed federal income taxes on an investment in the Fund. "Return After Taxes on Distributions" shows the effect of taxable distributions, but assumes that you still hold the Fund shares at the end of the period and so do not have any taxable gain or loss on your investment. "Return After Taxes on Distributions and Sale of Fund Shares" shows the effect of taxable distributions and any taxable gain or loss that would be realized if the Fund shares were purchased at the beginning and sold at the end of the specified period.

The after-tax returns are shown only for Class I shares, and are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes. Actual after-tax returns depend on an investor's tax situation and may differ from those shown, and the after-tax returns shown are not relevant to investors who hold their Fund shares through tax-advantaged arrangements, such as 401(k) plans or individual retirement accounts. After-tax returns for classes other than Class I will vary from returns shown for Class I. "Return After Taxes on Distributions and Sale of Fund Shares" may be higher than other returns for the same period due to a tax benefit of realizing a capital loss on the sale of Fund shares.

CALAMOS FAMILY OF FUNDS
6


Calamos Market Neutral Income Fund

AVERAGE ANNUAL TOTAL RETURNS — FOR THE PERIODS ENDED 12.31.22

    INCEPTION
DATE OF CLASS
 

ONE YEAR

 

FIVE YEAR

 

TEN YEAR

  SINCE
INCEPTION
 

Class A

   

9.4.90

                   

Load Adjusted Return before taxes

       

-6.65

%

   

2.13

%

   

2.60

%

   

5.57

%

 

Class C

   

2.16.00

                   

Load Adjusted Return before taxes

       

-6.18

%

   

1.82

%

   

2.33

%

   

3.26

%

 

Class I

   

5.10.00

                   

Return before taxes

       

-4.26

%

   

2.85

%

   

3.36

%

   

4.19

%

 

Return after taxes on distributions*

       

-4.66

%

   

2.30

%

   

2.68

%

   

2.98

%

 
Return after taxes on distributions and sale of
Fund shares*
       

-2.52

%

   

2.05

%

   

2.47

%

   

2.90

%

 

Class R6

   

6.23.20

                   

Load Adjusted Return before taxes

       

-4.12

%

   

N/A

     

N/A

     

2.01

%

 

Bloomberg U.S. Government/Credit Index

       

-13.58

%

   

0.21

%

   

1.16

%

   

4.07

%

 

Bloomberg Short Treasury 1-3 Month Index

       

1.52

%

   

1.23

%

   

0.73

%

   

1.51

%

 

*  Returns after taxes for Class I are provided because Class I shares represent the largest percentage of assets in the Calamos Family of Funds.

The Bloomberg Short Treasury 1-3 Month Index is generally considered representative of the performance of short-term money market investments and is provided to show how the Fund's performance compares to public obligations of the U.S. Treasury with maturities of 1-3 months.

Investment Adviser

Calamos Advisors LLC

PORTFOLIO MANAGER/
FUND TITLE (IF APPLICABLE)
  PORTFOLIO MANAGER
EXPERIENCE IN THE FUND
  PRIMARY TITLE
WITH INVESTMENT ADVISER
 

John P. Calamos, Sr. (President, Chairman)

 

since Fund's inception

 

Founder, Chairman, and Global CIO

 

Eli Pars

  9 years  

SVP, Sr. Co-Portfolio Manager

 

Jason Hill

  10 years  

SVP, Co-Portfolio Manager

 

David O'Donohue

  7.5 years  

SVP, Co-Portfolio Manager

 

Jimmy Young

  4 years  

SVP, Co-Portfolio Manager

 

Anthony Vecchiolla

 

since February 2023

 

VP, Co-Portfolio Manager

 

Other Important Information Regarding Fund Shares

For important information about purchase and sale of Fund shares, tax information, and financial intermediary compensation, please turn to "Other Important Information Regarding Fund Shares" on page 115 of the prospectus.

PROSPECTUS | March 1, 2023
7


Calamos Hedged Equity Fund

Investment Objective

Calamos Hedged Equity Fund's investment objective is to seek total return with lower volatility than equity markets.

Fees and Expenses of the Fund

The following table describes the fees and expenses that you may pay if you buy, hold and sell shares of the Fund. Investors may pay other fees, such as brokerage commissions and/or other forms of compensation to a financial intermediary, which are not reflected in the tables or the examples below. You may qualify for sales charge discounts on purchases of Class A shares if you and your family invest, or agree to invest in the future, at least $50,000 in Calamos Funds. More information about these and other discounts is available from your financial professional and under "Fund Facts — What classes of shares do the Funds offer?" on page 138 of the Fund's prospectus, in the Appendix to this prospectus and "Share Classes and Pricing of Shares" on page 66 of the Fund's statement of additional information.

Shareholder Fees (fees paid directly from your investment):

   

CLASS A

 

CLASS C

 

CLASS I

 

Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price)

   

4.75

%

   

None

     

None

   
Maximum Deferred Sales Charge (Load) (as a percentage of the lesser of the redemption price or
offering price)
   

None

     

1.00

%

   

None

   

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment):

   

CLASS A

 

CLASS C

 

CLASS I

 

Management Fees

   

0.74

%

   

0.74

%

   

0.74

%

 

Distribution and/or Service Fees (12b-1)

   

0.25

%

   

1.00

%

   

None

   

Other Expenses

   

0.17

%

   

0.17

%

   

0.17

%

 

Acquired Fund Fees and Expenses1

   

0.01

%

   

0.01

%

   

0.01

%

 

Total Annual Fund Operating Expenses

   

1.17

%

   

1.92

%

   

0.92

%

 

1  "Acquired Fund Fees and Expenses" include certain expenses incurred in connection with the Fund's investment in various money market funds and ETFs.

Example

This example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds. The example assumes that you invest $10,000 in the Fund for the time periods indicated and then either redeem or do not redeem your shares at the end of the reflected time periods. The example also assumes that your investment has a 5% return each year, that all dividends and capital gain distributions are reinvested, that you pay a maximum initial or contingent deferred sales charge and that the Fund's operating expenses remain the same. Although your actual performance and costs may be higher or lower, based on these assumptions, your costs would be:

You would pay the following expenses if you redeemed your shares at the end of the period:

   

One Year

 

Three Years

 

Five Years

 

Ten Years

 

Class A

   

589

     

829

     

1,088

     

1,828

   

Class C

   

295

     

603

     

1,037

     

2,243

   

Class I

   

94

     

293

     

509

     

1,131

   

CALAMOS FAMILY OF FUNDS
8


Calamos Hedged Equity Fund

You would pay the following expenses if you did not redeem your shares:

   

One Year

 

Three Years

 

Five Years

 

Ten Years

 

Class A

   

589

     

829

     

1,088

     

1,828

   

Class C

   

195

     

603

     

1,037

     

2,243

   

Class I

   

94

     

293

     

509

     

1,131

   

Portfolio Turnover

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when Fund shares are held in a taxable account. These costs, which are not reflected in the annual fund operating expenses or in the example, affect the Fund's performance. During the Fund's most recent fiscal year, the Fund's portfolio turnover rate was 32% of the average value of its portfolio.

Principal Investment Strategies

The Fund seeks to achieve total return with lower volatility than equity markets. Under normal circumstances, the Fund invests at least 80% of its net assets (plus any borrowings for investment purposes) in equity securities and securities with economic characteristics similar to stock or the equity markets. The Fund invests in a broadly diversified portfolio of equity securities while also writing (selling) index call and put options and/or entering into other options strategies on equity securities and/or broad based indices. The Fund may write call options (i) on a portion of the equity securities in the Fund's portfolio and (ii) on broad- based securities indexes (such as the S&P 500 or MSCI EAFE) or ETFs (exchange traded funds).

In addition, to seek to offset some of the risk of a potential decline in value of certain long positions, the Fund may also purchase put options on individual securities, broad-based securities indexes (such as the S&P 500), or ETFs. The Fund may also engage in active and frequent trading of portfolio securities.

Equity securities purchased by the Fund may include U.S. exchange-listed common stocks, options on equities, and American Depositary Receipts (ADRs). The Fund may also invest in fixed-income securities. The Fund may also invest in ETFs.

The Fund may use derivatives for hedging (attempting to reduce risk by offsetting one investment position with another) or non-hedging purposes. In particular, the Fund may hedge some or all of the currency exposure of foreign securities by entering into forward foreign currency contracts, futures or other derivatives.

The Fund's investment adviser seeks to lower the risks of investing in stocks by using a "top-down approach" of diversification by company, industry, sector, country and currency and focusing on macro-level investment themes. The Fund intends that its option-based risk management strategy will reduce the volatility inherent in investments in equity securities over time.

Principal Risks

An investment in the Fund is subject to risks, and you could lose money on your investment in the Fund. There can be no assurance that the Fund will achieve its investment objective. The risks associated with an investment in the Fund can increase during times of significant market volatility. Your investment in the Fund is not a deposit in a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency. The principal risks are presented in alphabetical order to facilitate finding particular risks and comparing them with other funds. Each risk summarized below is considered a "principal risk" of investing in the Fund, regardless of the order in which it appears. The principal risks of investing in the Fund include:

•  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.

PROSPECTUS | March 1, 2023
9


Calamos Hedged Equity Fund

•  Convertible Securities Risk — The value of a convertible security is influenced by changes in interest rates, with investment value declining as interest rates increase and increasing as interest rates decline. The credit standing of the issuer and other factors also may have an effect on the convertible security's investment value.

•  Correlation Risk — The effectiveness of the Fund's index option-based risk management strategy may be reduced if the performance of the Fund's equity portfolio does not correlate to that of the indices underlying its option positions.

•  Covered Call Writing Risk — As the writer of a covered call option on a security, the Fund foregoes, during the option's life, the opportunity to profit from increases in the market value of the security covering the call option above the sum of the premium and the exercise price of the call.

•  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.

•  Debt Securities Risk — Debt securities are subject to various risks, including interest rate risk, credit risk and default risk.

•  Interest Rate Risk — The value of debt securities generally decreases in periods when interest rates are rising. In addition, interest rate changes typically have a greater effect on prices of longer-term debt securities than shorter term debt securities. Recent fixed-income market events, including increases in volatility and interest rates, may expose the Fund to heightened interest rate risk and volatility.

•  Credit Risk — A debt security could deteriorate in quality to such an extent that its rating is downgraded or its market value declines relative to comparable securities. Changes in actual or perceived creditworthiness may occur quickly. If the Fund holds securities that have been downgraded, or that default on payment, the Fund's performance could be negatively affected.

•  Default Risk — A company that issues a debt security may be unable to fulfill its obligation to repay principal and interest. The lower a bond is rated, the greater its default risk. To the extent the Fund holds securities that have been downgraded, or that default on payment, its performance could be negatively affected.

•  Derivatives Risk — Derivatives are instruments, such as futures and forward foreign currency contracts, whose value is derived from that of other assets, rates or indices. The use of derivatives for non-hedging purposes may be considered more speculative than other types of investments. Derivatives can be used for hedging (attempting to reduce risk by offsetting one investment position with another) or non-hedging purposes. Hedging with derivatives may increase expenses, and there is no guarantee that a hedging strategy will work. While hedging can reduce or eliminate losses, it can also reduce or eliminate gains. In addition, derivative instruments are subject to counterparty risk, meaning that the party with whom the Fund enters into a derivative transaction may experience a significant credit event and/or may be unwilling or unable to make timely settlement payments or otherwise honor its obligations. Changes in the value of a derivative may not correlate perfectly with the underlying asset, rate or index, and the Fund could lose more than the principal amount invested.

•  Equity Securities Risk — The securities markets are volatile, and the market prices of the Fund's securities may decline generally. The price of equity securities fluctuates based on changes in a company's financial condition and overall market and economic conditions. If the market prices of the securities owned by the Fund (i.e., the Fund's long position) fall, the value of your investment in the Fund will decline.

•  Foreign Securities Risk — Risks associated with investing in foreign securities include fluctuations in the exchange rates of foreign currencies that may affect the U.S. dollar value of a security, the possibility of substantial price volatility as a result of political and economic instability in the foreign country, less public information about issuers of securities, different securities regulation, different accounting, auditing and financial reporting standards and less liquidity than in U.S. markets.

CALAMOS FAMILY OF FUNDS
10


Calamos Hedged Equity Fund

•  Forward Foreign Currency Contract Risk — Forward foreign currency 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 foreign currency 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 with whom the Fund enters into the derivatives transaction (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/or may be unwilling or unable to make timely settlement payments or otherwise honor its obligations.

•  Options Risk — The Fund's ability to close out its position as a purchaser or seller of an over-the-counter or exchange- listed put or call option is dependent, in part, upon the liquidity of the options market. There are significant differences between the securities and options markets that could result in an imperfect correlation among these markets, causing a given transaction not to achieve its objectives. The Fund's ability to utilize options successfully will depend on the ability of the Fund's investment adviser to predict pertinent market movements, which cannot be assured. The Fund may also purchase or write over-the-counter put or call options, which involves risks different from, and possibly greater than, the risks associated with exchange-listed put or call options. In some instances, over-the-counter put or call options may expose the Fund to the risk that a counterparty may be unable or unwilling to perform according to a contract, and that any deterioration in a counterparty's creditworthiness could adversely affect the instrument. In addition, the Fund may be exposed to a risk that losses may exceed the amount originally invested.

•  Other Investment Companies (including ETFs) Risk — The Fund may invest in the securities of other investment companies to the extent that such investments are consistent with the Fund's investment objective and the policies are permissible under the 1940 Act. Investments in the securities of other investment companies, including ETFs, may involve duplication of advisory fees and certain other expenses. Additionally, 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.

•  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.

•  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.

•  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 of its board of trustees, the Fund 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.

PROSPECTUS | March 1, 2023
11


Calamos Hedged Equity 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.

•  Securities Lending Risk — The Fund may lend its portfolio securities to broker-dealers and banks in order to generate additional income for the Fund. Any such loan must be continuously secured by collateral in cash or cash equivalents maintained on a current basis in an amount at least equal to the market value of the securities loaned by the Fund. In the event of bankruptcy or other default of a borrower of portfolio securities, the Fund could experience both delays in liquidating the loan collateral or recovering the loaned securities and losses, including (a) possible decline in the value of the collateral or in the value of the securities loaned during the period while the Fund seeks to enforce its rights thereto, (b) possible subnormal levels of income and lack of access to income during this period, and (c) expenses of enforcing its rights. In an effort to reduce these risks, the Fund's securities lending agent monitors, and reports to Calamos Advisors on, the creditworthiness of the firms to which a Fund lends securities. The Fund may also experience losses as a result of a diminution in value of its cash collateral investments.

•  Short Sale Risk — The Fund may incur a loss (without limit) as a result of a short sale if the market value of the borrowed security (i.e., the Fund's short position) increases between the date of the short sale and the date the Fund replaces the security. The Fund may be unable to repurchase the borrowed security at a particular time or at an acceptable price.

•  Tax Risk — The federal income tax treatment of convertible securities or other securities in which the Fund may invest may not be clear or may be subject to recharacterization by the Internal Revenue Service. It could be more difficult to comply with the tax requirements applicable to regulated investment companies if the tax characterization of investments or the tax treatment of the income from such investments were successfully challenged by the Internal Revenue Service. Any such failure to comply with the rules applicable to regulated investment companies could cause the Fund to fail to qualify as such.

Fund Performance

The following bar chart and table indicate the risks of investing in the Fund by showing changes in the Fund's performance from calendar year to calendar year and how the Fund's average annual total returns compare with those of a broad measure of market performance. All returns include the reinvestment of dividends and distributions. As always, please note that the Fund's past performance (before and after taxes) cannot predict how it will perform in the future. Updated performance information is available at no cost by visiting www.calamos.com or by calling 800.582.6959.

CLASS I* ANNUAL TOTAL RETURN FOR YEARS ENDED 12.31

Highest Quarterly Return:

   

10.84

% (6.30.2020)

 

Lowest Quarterly Return:

   

-10.28

% (6.30.2022)

 

*  Annual returns for Class I are provided because Class I shares represent the largest percentage of assets in the Calamos Family of Funds.

CALAMOS FAMILY OF FUNDS
12


Calamos Hedged Equity Fund

Average Annual Total Returns as of 12.31.22

The following table shows how the Fund's average annual performance (before and after taxes) for the one- and five-year periods ended December 31, 2022 and since the Fund's inception compared with broad measures of market performance. "Since Inception" returns shown for each index are returns since the inception of the Fund's Class A shares, or since the nearest subsequent month end when comparative index data is available only for full monthly periods. The after-tax returns show the impact of assumed federal income taxes on an investment in the Fund. "Return After Taxes on Distributions" shows the effect of taxable distributions, but assumes that you still hold the Fund shares at the end of the period and so do not have any taxable gain or loss on your investment. "Return After Taxes on Distributions and Sale of Fund Shares" shows the effect of taxable distributions and any taxable gain or loss that would be realized if the Fund shares were purchased at the beginning and sold at the end of the specified period.

The after-tax returns are shown only for Class I shares, and are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes. Actual after-tax returns depend on an investor's tax situation and may differ from those shown, and the after-tax returns shown are not relevant to investors who hold their Fund shares through tax-advantaged arrangements, such as 401(k) plans or individual retirement accounts. After-tax returns for classes other than Class I will vary from returns shown for Class I. "Return After Taxes on Distributions and Sale of Fund Shares" may be higher than other returns for the same period due to a tax benefit of realizing a capital loss on the sale of Fund shares.

AVERAGE ANNUAL TOTAL RETURNS — FOR THE PERIODS ENDED 12.31.22

    INCEPTION
DATE OF CLASS
 

ONE YEAR

 

FIVE YEAR

  SINCE
INCEPTION
 

Class A

   

12.31.14

               

Load Adjusted Return before taxes

       

-15.50

%

   

3.69

%

   

4.00

%

 

Class C

   

12.31.14

               

Load Adjusted Return before taxes

       

-12.85

%

   

3.98

%

   

3.89

%

 

Class I

   

12.31.14

               

Return before taxes

       

-11.11

%

   

4.99

%

   

4.92

%

 

Return after taxes on distributions*

       

-11.38

%

   

4.65

%

   

4.56

%

 

Return after taxes on distributions and sale of Fund shares*

       

-6.58

%

   

3.83

%

   

3.82

%

 

S&P 500 Index

       

-18.11

%

   

9.42

%

   

10.17

%

 

Bloomberg U.S. Aggregate Bond Index

       

-13.01

%

   

0.02

%

   

0.85

%

 

*  Returns after taxes for Class I are provided because Class I shares represent the largest percentage of assets in the Calamos Family of Funds.

The Bloomberg U.S. Aggregate Bond Index shows how the Fund's performance compares to an index that covers the U.S.-denominated, investment-grade, fixed-rate, taxable bond market of SEC-registered securities. The index includes bonds from the Treasury, Government-Related, Corporate, MBS (agency fixed-rate and hybrid ARM pass-throughs), ABS, and CMBS sectors.

PROSPECTUS | March 1, 2023
13


Calamos Hedged Equity Fund

Investment Adviser

Calamos Advisors LLC

PORTFOLIO MANAGER/
FUND TITLE (IF APPLICABLE)
  PORTFOLIO MANAGER
EXPERIENCE IN THE FUND
  PRIMARY TITLE
WITH INVESTMENT ADVISER
 

John P. Calamos, Sr. (President, Chairman)

 

since Fund's inception

 

Founder, Chairman, and Global CIO

 

Eli Pars

 

since Fund's inception

 

SVP, Sr. Co-Portfolio Manager

 

Jason Hill

 

since Fund's inception

 

SVP, Co-Portfolio Manager

 

David O'Donohue

  7.5 years  

SVP, Co-Portfolio Manager

 

Jimmy Young

  4 years  

SVP, Co-Portfolio Manager

 

Anthony Vecchiolla

 

since February 2023

 

VP, Co-Portfolio Manager

 

Other Important Information Regarding Fund Shares

For important information about purchase and sale of Fund shares, tax information, and financial intermediary compensation, please turn to "Other Important Information Regarding Fund Shares" on page 115 of the prospectus.

CALAMOS FAMILY OF FUNDS
14


Calamos Phineus Long/Short Fund

Investment Objective

Calamos Phineus Long/Short Fund's investment objective is to seek strong, risk-adjusted and absolute returns in the context of prevailing market conditions across the global equity universe.

Fees and Expenses of the Fund

The following table describes the fees and expenses that you may pay if you buy, hold and sell shares of the Fund. Investors may pay other fees, such as brokerage commissions and/or other forms of compensation to a financial intermediary, which are not reflected in the tables or the examples below. You may qualify for sales charge discounts on purchases of Class A shares if you and your family invest, or agree to invest in the future, at least $50,000 in Calamos Funds. More information about these and other discounts is available from your financial professional and under "Fund Facts — What classes of shares does the Fund offer?" on page 138 of the Fund's prospectus, in the Appendix to this prospectus and "Share Classes and Pricing of Shares" on page 66 of the Fund's statement of additional information.

Shareholder Fees (fees paid directly from your investment):

   

CLASS A

 

CLASS C

 

CLASS I

 

Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price)

   

4.75

%

   

None

     

None

   
Maximum Deferred Sales Charge (Load) (as a percentage of the lesser of the redemption price or
offering price)
   

None

     

1.00

%

   

None

   

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment):

   

CLASS A

 

CLASS C

 

CLASS I

 

Management Fees

   

1.24

%

   

1.24

%

   

1.24

%

 

Distribution and/or Service Fees (12b-1)

   

0.25

%

   

1.00

%

   

None

   

Dividend and Interest Expense on Short Sales1

   

0.74

%

   

0.73

%

   

0.75

%

 

Other Expenses

   

0.15

%

   

0.15

%

   

0.15

%

 

Acquired Fund Fees and Expenses2

   

0.01

%

   

0.01

%

   

0.01

%

 

Total Annual Fund Operating Expenses

   

2.39

%

   

3.13

%

   

2.15

%

 

1  "Dividend and Interest Expense on Short Sales" reflect interest expense and dividends paid on borrowed securities. Interest expenses result from the Fund's use of prime brokerage arrangements to execute short sales. Dividends paid on borrowed securities are an expense of short sales. Such expenses are required to be treated as a Fund expense for accounting purposes and are not payable to Calamos Advisors LLC. Any interest expense amount or dividends paid on securities sold short will vary based on the Fund's use of those investments as an investment strategy best suited to seek the objective of the Fund.

2  "Acquired Fund Fees and Expenses" include certain expenses incurred in connection with the Fund's investment in various money market funds, affiliated mutual funds, and ETFs.

Example

This example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds. The example assumes that you invest $10,000 in the Fund for the time periods indicated and then either redeem or do not redeem your shares at the end of the reflected time periods. The example also assumes that your investment has a 5% return each year, that all dividends and capital gain distributions are reinvested, that you pay a maximum initial or contingent deferred sales charge and that the Fund's operating expenses remain the same. Although your actual performance and costs may be higher or lower, based on these assumptions, your costs would be:

You would pay the following expenses if you redeemed your shares at the end of the period:

   

One Year

 

Three Years

 

Five Years

 

Ten Years

 

Class A

   

706

     

1,185

     

1,690

     

3,072

   

Class C

   

416

     

966

     

1,640

     

3,439

   

Class I

   

218

     

673

     

1,154

     

2,483

   

PROSPECTUS | March 1, 2023
15


Calamos Phineus Long/Short Fund

You would pay the following expenses if you did not redeem your shares:

   

One Year

 

Three Years

 

Five Years

 

Ten Years

 

Class A

   

706

     

1,185

     

1,690

     

3,072

   

Class C

   

316

     

966

     

1,640

     

3,439

   

Class I

   

218

     

673

     

1,154

     

2,483

   

Portfolio Turnover

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when Fund shares are held in a taxable account. These costs, which are not reflected in the annual fund operating expenses or in the example, affect the Fund's performance. During the Fund's most recent fiscal period, the Fund's portfolio turnover rate was 214% of the average value of its portfolio.

Principal Investment Strategies

Under normal circumstances, the Fund aims to achieve its investment objective primarily by investing globally in publicly listed equity securities, including common stock and American Depositary Receipts ("ADRs"), of issuers of all market capitalizations that operate in the knowledge-based sectors such as technology, communications and media, as well as financial services and healthcare, and other investment companies, including exchange-traded funds ("ETFs"), that track or otherwise provide exposure to such sectors. The Fund's investment adviser (the "Advisor") believes that the heterogeneous, disruptive and volatile nature of many of these sectors is well suited for long/short equity investing. Long investing generally involves buying a security expecting to profit from an increase in its price. Short investing generally involves selling a security that the Fund does not own expecting to profit from a decline in its price at a later time. The Advisor will also consider investing in other sectors if, in the Advisor's opinion, such long and short exposures have favorable potential for contributing value. The Fund may maintain long and short positions through the use of derivative instruments, such as options, futures and forward contracts, without investing directly in the underlying asset. The Fund may also use derivative instruments to attempt to both increase the return of the Fund and hedge (protect) the value of the Fund's assets. The Fund may also invest in cash and cash equivalents.

The Advisor pursues a fundamental, global approach that incorporates a blend of top-down and bottom-up considerations. The advantages of its investment process are based upon: 1) a comprehensive assessment of what drives share prices; 2) how companies and industries are analyzed; and 3) the flexible management of style, capitalization and country factors. The Advisor believes that flexible asset allocation across the global equity universe, with less emphasis upon the traditional role of benchmarks, provides the potential for excess returns.

The Advisor's approach is primarily derived from its assessment of corporate and economic fundamentals. Equally, the Fund's strategy allows for all investment styles (for example, growth versus value, small versus large capitalization) to be considered depending upon a company's business model, prevailing market conditions and the economic cycle. The Advisor believes that stocks with common style characteristics can behave similarly, often in response to the economic cycle, and that these characteristics are an additional source of return that should be identified.

Principal Risks

An investment in the Fund is subject to risks, and you could lose money on your investment in the Fund. There can be no assurance that the Fund will achieve its investment objective. The risks associated with an investment in the Fund can increase during times of significant market volatility. Under certain conditions, even if the value of the Fund's long positions are rising, this could be offset by declining values of the Fund's short positions. Conversely, it is possible that rising values of the Fund's short positions could be offset by declining values of the Fund's long positions. In either scenario the Fund may experience losses. In a market where the value of both the Fund's long and short positions are declining, the Fund may experience substantial losses. Your investment in the Fund is not a deposit in a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency. The principal risks are presented in alphabetical order to

CALAMOS FAMILY OF FUNDS
16


Calamos Phineus Long/Short Fund

facilitate finding particular risks and comparing them with other funds. Each risk summarized below is considered a "principal risk" of investing in the Fund, regardless of the order in which it appears. The principal risks of investing in the Fund include:

•  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.

•  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.

•  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.

•  Derivatives Risk — Derivatives are instruments, such as futures, options, and forward foreign currency contracts, whose value is derived from that of other assets, rates, or indices. The use of derivatives for non-hedging purposes may be considered more speculative than other types of investments. Derivatives can be used for hedging (attempting to reduce risk by offsetting one investment position with another) or non-hedging purposes. Hedging with derivatives may increase expenses, and there is no guarantee that a hedging strategy will work. While hedging can reduce or eliminate losses, it can also reduce or eliminate gains. In addition, derivative instruments are subject to counterparty risk, meaning that the party with whom the Fund enters into the derivatives transaction may experience a significant credit event and/or may be unwilling or unable to make timely settlement payments or otherwise honor its obligations. Changes in the value of a derivative may not correlate perfectly with the underlying asset, rate or index, and the Fund could lose more than the principal amount invested.

•  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 hurt their economies and securities markets.

•  Equity Securities Risk — The securities markets are volatile, and the market prices of the Fund's securities may decline generally. The price of equity securities fluctuates based on changes in a company's financial condition and overall market and economic conditions. If the market prices of the securities owned by the Fund (i.e., the Fund's long position) fall, the value of your investment in the Fund will decline.

•  Foreign Securities Risk — Risks associated with investing in foreign securities include fluctuations in the exchange rates of foreign currencies that may affect the U.S. dollar value of a security, the possibility of substantial price volatility as a result of political and economic instability in the foreign country, less public information about issuers of securities, different securities regulation, different accounting, auditing and financial reporting standards and less liquidity than in U.S. markets.

•  Forward Foreign Currency Contract Risk — Forward foreign currency 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 foreign currency 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

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17


Calamos Phineus Long/Short Fund

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 options. Forward contracts involve a negotiated obligation to purchase or sell an asset at a future date (with or without delivery required), which may be any fixed number of days from the date of the contract agreed upon by the parties, at a price set at the time of the contract. Forward contracts are not traded on exchanges; rather, a bank or dealer will act as agent or as principal in order to make or take future delivery of a specified lot of a particular security or currency for the Fund's account. Futures and forward contracts are subject to counterparty risk, meaning that the party with whom the Fund enters into the derivatives transaction (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/or may be unwilling or unable to make timely settlement payments or otherwise honor its obligations.

•  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.

•  Leveraging Risk — Leverage is the potential for the Fund to participate in gains and losses on an amount that exceeds the Fund's investment. Leveraging risk is the risk that certain transactions of the Fund may cause the Fund to be more volatile and experience greater losses than if it had not been leveraged. The Fund's use of short sales and investments in derivatives subject the Fund to leveraging risk.

•  Liquidity Risk — Liquidity risk exists when particular investments are difficult to purchase or sell. The Fund's investments in illiquid securities may reduce the returns of the Fund because it may be unable to sell the illiquid securities at an advantageous time or price.

•  Options Risk — The Fund's ability to close out its position as a purchaser or seller of an over-the-counter or exchange- listed put or call option is dependent, in part, upon the liquidity of the options market. There are significant differences between the securities and options markets that could result in an imperfect correlation among these markets, causing a given transaction not to achieve its objectives. The Fund's ability to utilize options successfully will depend on the ability of the Fund's investment adviser to predict pertinent market movements, which cannot be assured. The Fund may also purchase or write over-the-counter put or call options, which involves risks different from, and possibly greater than, the risks associated with exchange-listed put or call options. In some instances, over-the-counter put or call options may expose the Fund to the risk that a counterparty may be unable or unwilling to perform according to a contract, and that any deterioration in a counterparty's creditworthiness could adversely affect the instrument. In addition, the Fund may be exposed to a risk that losses may exceed the amount originally invested.

•  Other Investment Companies (including ETFs) Risk — The Fund may invest in the securities of other investment companies to the extent that such investments are consistent with the Fund's investment objective and the policies are permissible under the 1940 Act. Investments in the securities of other investment companies, including ETFs, may involve duplication of advisory fees and certain other expenses. Additionally, 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.

•  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.

•  Portfolio Turnover Risk — The portfolio manager 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

CALAMOS FAMILY OF FUNDS
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Calamos Phineus Long/Short Fund

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.

•  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.

•  Securities Lending Risk — The Fund may lend its portfolio securities to broker-dealers and banks in order to generate additional income for the Fund. Any such loan must be continuously secured by collateral in cash or cash equivalents maintained on a current basis in an amount at least equal to the market value of the securities loaned by the Fund. In the event of bankruptcy or other default of a borrower of portfolio securities, the Fund could experience both delays in liquidating the loan collateral or recovering the loaned securities and losses, including (a) possible decline in the value of the collateral or in the value of the securities loaned during the period while the Fund seeks to enforce its rights thereto, (b) possible subnormal levels of income and lack of access to income during this period, and (c) expenses of enforcing its rights. In an effort to reduce these risks, the Fund's securities lending agent monitors, and reports to Calamos Advisors on, the creditworthiness of the firms to which a Fund lends securities. The Fund may also experience losses as a result of a diminution in value of its cash collateral investments.

•  Short Sale Risk — The Fund may incur a loss (without limit) as a result of a short sale if the market value of the borrowed security (i.e., the Fund's short position) increases between the date of the short sale and the date the Fund replaces the security. The Fund may be unable to repurchase the borrowed security at a particular time or at an acceptable price.

•  Small and Mid-Sized Company Stock Risk — Small to mid-sized company stocks have historically been subject to greater investment risk than large company stock. The prices of small to mid-sized company stocks tend to be more volatile and less liquid than large company stocks. Small and mid-sized companies may have no or relatively short operating histories, or be newly formed public companies. Some of these companies have aggressive capital structures, including high debt levels, or are involved in rapidly growing or changing industries and/or new technologies, which pose additional risks.

Fund Performance

The following bar chart and table indicate the risks of investing in the Fund by showing changes in the Fund's performance from calendar year to calendar year and how the Fund's average annual total returns compare with those of a broad measure of market performance. All returns include the reinvestment of dividends and distributions. The performance shown in the bar chart and performance table for the years prior to 2017 is that of another investment vehicle (the "Phineus Predecessor Fund") prior to the commencement of the Fund's operations. The Phineus Predecessor Fund was reorganized into Class I shares of the Fund on April 6, 2016. On October 1, 2015, the parent company of Calamos Advisors purchased Phineus Partners LP ("Phineus"), the prior general partner and investment manager to the Phineus Predecessor Fund and investment manager to the Phineus Predecessor Fund's master fund. Calamos Advisors served as the investment manager to the Phineus Predecessor Fund's master fund from October 1, 2015 to April 5, 2016 and the general partner and investment manager of the Phineus Predecessor Fund from February 25, 2016 and April 5, 2016. The Phineus Predecessor Fund commenced operations on May 1, 2002 and, since that time, has had various periods where it implemented its investment strategy directly on a stand-alone basis or indirectly through its investment in a master fund, which had the same investment policies, objectives, guidelines and restrictions as the Phineus Predecessor Fund.

Regardless of whether the Phineus Predecessor Fund operated as a stand-alone fund or invested indirectly through a master fund, Phineus and Calamos Advisors managed the Phineus Predecessor Fund's assets using investment policies, objectives, guidelines and restrictions that were in all material respects equivalent to those of the Fund. The Phineus Predecessor Fund performance information in the bar chart and table has been adjusted to reflect Class I share, and with respect to the table, Class A and Class C share expenses. However, the Phineus Predecessor Fund was not a registered mutual fund and so it was

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19


Calamos Phineus Long/Short Fund

not subject to the same investment and tax restrictions as the Fund. If it had been, the Phineus Predecessor Fund's performance may have been lower. As always, please note that the Fund's past performance (before and after taxes) cannot predict how it will perform in the future. Updated Fund performance information is available at no cost by visiting www.calamos.com or by calling 800.582.6959.

CLASS I* ANNUAL TOTAL RETURN FOR YEARS ENDED 12.31

Highest Quarterly Return:

   

24.69

% (12.31.2020)

 

Lowest Quarterly Return:

   

-11.48

% (3.31.2020)

 

*  Annual returns for Class I are provided because Class I shares represent the largest percentage of assets in the Calamos Family of Funds.

Average Annual Total Returns as of 12.31.22

The following table shows how the Fund's average annual performance (before and after taxes) for the one-, five-, and ten- year periods ended December 31, 2022 and since the Phineus Predecessor Fund's inception compare with broad measures of market performance. "Since Inception" returns shown for each index are returns since the inception of the Phineus Predecessor Fund, or since the nearest subsequent month end when comparative index data is available only for full monthly periods. The after-tax returns show the impact of assumed federal income taxes on an investment in the Fund. "Return After Taxes on Distributions" shows the effect of taxable distributions, but assumes that you still hold the Fund shares at the end of the period and so do not have any taxable gain or loss on your investment. "Return After Taxes on Distributions and Sale of Fund Shares" shows the effect of taxable distributions and any taxable gain or loss that would be realized if the Fund shares were purchased at the beginning and sold at the end of the specified period.

The after-tax returns are shown only for Class I shares, and are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes. Actual after-tax returns depend on an investor's tax situation and may differ from those shown, and the after-tax returns shown are not relevant to investors who hold their Fund shares through tax-advantaged arrangements, such as 401(k) plans or individual retirement accounts. After-tax returns for classes other than Class I shares will vary from returns shown for Class I shares. "Return After Taxes on Distributions and Sale of Fund Shares" may be higher than other returns for the same period due to a tax benefit of realizing a capital loss on the sale of Fund shares.

CALAMOS FAMILY OF FUNDS
20


Calamos Phineus Long/Short Fund

AVERAGE ANNUAL TOTAL RETURNS — FOR THE PERIODS ENDED 12.31.22

    INCEPTION
DATE OF CLASS
 

ONE YEAR

 

FIVE YEAR

 

TEN YEAR

  SINCE
INCEPTION
 

Class A

   

5.1.02

                   

Load Adjusted Return before taxes

       

-5.85

%

   

3.28

%

   

6.13

%

   

9.37

%

 

Class C

   

5.1.02

                   

Load Adjusted Return before taxes

       

-2.93

%

   

3.50

%

   

5.84

%

   

8.82

%

 

Class I

   

5.1.02

                   

Return before taxes

       

-0.96

%

   

4.53

%

   

6.91

%

   

9.91

%

 

Return after taxes on distributions*

       

-0.97

%

   

4.20

%

   

6.66

%

   

9.79

%

 
Return after taxes on distributions and sale of
Fund shares*
       

-0.57

%

   

3.36

%

   

5.47

%

   

8.63

%

 

S&P 500 Index

       

-18.11

%

   

9.42

%

   

12.56

%

   

8.46

%

 

MSCI World Index

       

-17.73

%

   

6.69

%

   

9.44

%

   

7.48

%

 

*  Returns after taxes for Class I are provided because Class I shares represent the largest percentage of assets in the Calamos Family of Funds.

The MSCI World Index is designed to measure the equity market performance of developed markets. The MSCI World Index is provided to show how the Fund's performance compares with the returns of an index of securities similar to those in which the Fund invests.

Investment Adviser

Calamos Advisors LLC

PORTFOLIO MANAGER/
FUND TITLE (IF APPLICABLE)
  PORTFOLIO MANAGER
EXPERIENCE IN THE FUND
  PRIMARY TITLE
WITH INVESTMENT ADVISER
 

Michael Grant

 

since Fund's inception

 

SVP, Sr. Co-Portfolio Manager

 

Other Important Information Regarding Fund Shares

For important information about purchase and sale of Fund shares, tax information, and financial intermediary compensation, please turn to "Other Important Information Regarding Fund Shares" on page 115 of the prospectus.

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21


Calamos Convertible Fund

Investment Objective

Calamos Convertible Fund's primary objective is current income, with growth as its secondary objective.

Fees and Expenses of the Fund

The following table describes the fees and expenses that you may pay if you buy, hold, and sell shares of the Fund. Investors may pay other fees, such as brokerage commissions and/or other forms of compensation to a financial intermediary, which are not reflected in the tables or the examples below. You may qualify for sales charge discounts on purchase of Class A shares if you and your family invest, or agree to invest in the future, at least $100,000 in Calamos Funds. More information about these and other discounts is available from your financial professional and under "Fund Facts — What classes of shares do the Funds offer?" on page 138 of the Fund's prospectus, in the Appendix to this prospectus and "Share Classes and Pricing of Shares" on page 66 of the Fund's statement of additional information.

Shareholder Fees (fees paid directly from your investment):

   

CLASS A

 

CLASS C

 

CLASS I

 

Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price)

   

2.25

%

   

None

     

None

   
Maximum Deferred Sales Charge (Load) (as a percentage of the lesser of the redemption price or
offering price)
   

None

     

1.00

%

   

None

   

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment):

   

CLASS A

 

CLASS C

 

CLASS I

 

Management Fees

   

0.71

%

   

0.71

%

   

0.71

%

 

Distribution and/or Service Fees (12b-1)

   

0.25

%

   

1.00

%

   

None

   

Other Expenses

   

0.14

%

   

0.14

%

   

0.14

%

 

Total Annual Fund Operating Expenses

   

1.10

%

   

1.85

%

   

0.85

%

 

Example

This example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds. The example assumes that you invest $10,000 in the Fund for the time periods indicated and then either redeem or do not redeem your shares at the end of the reflected time periods. The example also assumes that your investment has a 5% return each year, that all dividends and capital gain distributions are reinvested, that you pay a maximum initial or contingent deferred sales charge and that the Fund's operating expenses remain the same. Although your actual performance and costs may be higher or lower, based on these assumptions, your costs would be:

You would pay the following expenses if you redeemed your shares at the end of the period:

   

One Year

 

Three Years

 

Five Years

 

Ten Years

 

Class A

   

335

     

567

     

818

     

1,535

   

Class C

   

288

     

582

     

1,001

     

2,169

   

Class I

   

87

     

271

     

471

     

1,049

   

You would pay the following expenses if you did not redeem your shares:

   

One Year

 

Three Years

 

Five Years

 

Ten Years

 

Class A

   

335

     

567

     

818

     

1,535

   

Class C

   

188

     

582

     

1,001

     

2,169

   

Class I

   

87

     

271

     

471

     

1,049

   

CALAMOS FAMILY OF FUNDS
22


Calamos Convertible Fund

Portfolio Turnover

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when Fund shares are held in a taxable account. These costs, which are not reflected in the annual fund operating expenses or in the example, affect the Fund's performance. During the most recent fiscal year, the Fund's portfolio turnover rate was 39% of the average value of its portfolio.

Principal Investment Strategies

The Fund invests mainly in a diversified portfolio of convertible securities (including synthetic convertible instruments) issued by both U.S. and foreign companies without regard to market capitalization. These convertible securities may be either debt securities or preferred stocks that can be exchanged for common stock. Under normal circumstances, the Fund invests at least 80% of its net assets (plus any borrowings) in convertible securities.

A synthetic convertible instrument is a financial instrument (or two or more securities held in tandem) that is designed to simulate the economic characteristics of a convertible security through the combined features of a debt instrument and a security providing an option on an equity security. The Fund may establish a synthetic convertible instrument by combining fixed-income securities (which may be either convertible or non-convertible) with the right to acquire equity securities. In establishing a synthetic instrument, the Fund may combine a basket of fixed-income securities with a basket of warrants or options that together produce economic characteristics similar to a convertible security. Within each basket of fixed-income securities and warrants or options, different companies may issue the fixed-income and convertible components, which may be purchased separately and at different times.

The Fund may invest up to 25% of its net assets in foreign securities, but generally will invest approximately 5% to 15% of its net assets in foreign securities. Foreign securities are securities issued by issuers that are organized under the laws of a foreign country or that have a substantial portion of their operations or assets in a foreign country or countries, or that derive a substantial portion of their revenue or profits from businesses, investments or sales outside of the United States. The Fund may also invest in foreign securities that are represented in the United States securities markets by American Depositary Receipts ("ADRs") or similar depository arrangements. The Fund's foreign debt investments can be denominated in U.S. dollars or in foreign currencies. Debt securities issued by a foreign government may not be supported by the "full faith and credit" of that government.

In analyzing the appreciation potential of the underlying common stock and the default risk of the convertible security, the Fund generally considers the issuer's financial soundness, ability to make interest and dividend payments, earnings and cash flow forecast and quality of management. The investment adviser takes environmental, social and governance ("ESG") factors into account in making investment decisions. The Fund's investment adviser seeks to lower the risks of investing in stocks by using a "top-down approach" of diversification by company, industry, sector, country and currency and focusing on macro-level investment themes. Consistent with the Fund's investment objective and principal investment strategies the Fund's investment adviser views the strategies as low volatility equity strategies and attempts to achieve equity-like returns with lower than equity market risk by managing a portfolio that it believes will exhibit less volatility over full market cycles.

Principal Risks

An investment in the Fund is subject to risks, and you could lose money on your investment in the Fund. There can be no assurance that the Fund will achieve its investment objective. The risks associated with an investment in the Fund can increase during times of significant market volatility. Your investment in the Fund is not a deposit in a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency. The principal risks are presented in alphabetical order to facilitate finding particular risks and comparing them with other funds. Each risk summarized below is

PROSPECTUS | March 1, 2023
23


Calamos Convertible Fund

considered a "principal risk" of investing in the Fund, regardless of the order in which it appears. The principal risks of investing in the Fund include:

•  Convertible Securities Risk — The value of a convertible security is influenced by changes in interest rates, with investment value declining as interest rates increase and increasing as interest rates decline. The credit standing of the issuer and other factors also may have an effect on the convertible security's investment value.

•  Debt Securities Risk — Debt securities are subject to various risks, including interest rate risk, credit risk and default risk.

•  Interest Rate Risk — The value of debt securities generally decreases in periods when interest rates are rising. In addition, interest rate changes typically have a greater effect on prices of longer-term debt securities than shorter term debt securities. Recent fixed-income market events, including increases in volatility and interest rates, may expose the Fund to heightened interest rate risk and volatility.

•  Credit Risk — A debt security could deteriorate in quality to such an extent that its rating is downgraded or its market value declines relative to comparable securities. Changes in actual or perceived creditworthiness may occur quickly. If the Fund holds securities that have been downgraded, or that default on payment, the Fund's performance could be negatively affected.

•  Default Risk — A company that issues a debt security may be unable to fulfill its obligation to repay principal and interest. The lower a bond is rated, the greater its default risk. To the extent the Fund holds securities that have been downgraded, or that default on payment, its performance could be negatively affected.

•  Equity Securities Risk — The securities markets are volatile, and the market prices of the Fund's securities may decline generally. The price of equity securities fluctuates based on changes in a company's financial condition and overall market and economic conditions. If the market prices of the securities owned by the Fund fall, the value of your investment in the Fund will decline.

•  Foreign Securities Risk — Risks associated with investing in foreign securities include fluctuations in the exchange rates of foreign currencies that may affect the U.S. dollar value of a security, the possibility of substantial price volatility as a result of political and economic instability in the foreign country, less public information about issuers of securities, different securities regulation, different accounting, auditing and financial reporting standards and less liquidity than in U.S. markets.

•  Forward Foreign Currency Contract Risk — Forward foreign currency 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 foreign currency 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.

•  High Yield Risk — High yield securities and unrated securities of similar credit quality (commonly known as "junk bonds") are subject to greater levels of credit and liquidity risks. High yield securities are considered primarily speculative with respect to the issuer's continuing ability to make principal and interest payments.

•  Liquidity Risk — Liquidity risk exists when particular investments are difficult to purchase or sell. The Fund's investments in illiquid securities may reduce the returns of the Fund because it may be unable to sell the illiquid securities at an advantageous time or price.

•  Options Risk — The Fund's ability to close out its position as a purchaser or seller of an over-the-counter or exchange- listed put or call option is dependent, in part, upon the liquidity of the option market. There are significant differences between the securities and options markets that could result in an imperfect correlation among these markets, causing a given transaction not to achieve its objectives. The Fund's ability to utilize options successfully will depend on the ability of the Fund's investment adviser to predict pertinent market movements, which cannot be assured.

•  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.

CALAMOS FAMILY OF FUNDS
24


Calamos Convertible Fund

•  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 of its board of trustees, the Fund 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.

•  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.

•  Securities Lending Risk — The Fund may lend its portfolio securities to broker-dealers and banks in order to generate additional income for the Fund. Any such loan must be continuously secured by collateral in cash or cash equivalents maintained on a current basis in an amount at least equal to the market value of the securities loaned by the Fund. In the event of bankruptcy or other default of a borrower of portfolio securities, the Fund could experience both delays in liquidating the loan collateral or recovering the loaned securities and losses, including (a) possible decline in the value of the collateral or in the value of the securities loaned during the period while the Fund seeks to enforce its rights thereto, (b) possible subnormal levels of income and lack of access to income during this period, and (c) expenses of enforcing its rights. In an effort to reduce these risks, the Fund's securities lending agent monitors, and reports to Calamos Advisors on, the creditworthiness of the firms to which a Fund lends securities. The Fund may also experience losses as a result of a diminution in value of its cash collateral investments.

•  Small and Mid-Sized Company Risk — Small and mid-sized company stocks have historically been subject to greater investment risk than large company stocks. The prices of small and mid-sized company stocks tend to be more volatile than prices of large company stocks.

•  Synthetic Convertible Instruments Risk — The value of a synthetic convertible instrument will respond differently to market fluctuations than a convertible security 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.

•  Tax Risk — The federal income tax treatment of convertible securities or other securities in which the Fund may invest may not be clear or may be subject to recharacterization by the Internal Revenue Service. It could be more difficult to comply with the tax requirements applicable to regulated investment companies if the tax characterization of investments or the tax treatment of the income from such investments were successfully challenged by the Internal Revenue Service. Any such failure to comply with the rules applicable to regulated investment companies could cause the Fund to fail to qualify as such.

Fund Performance

The following bar chart and table indicate the risks of investing in the Fund by showing changes in the Fund's performance from calendar year to calendar year and how the Fund's average annual total returns compare with those of a broad measure of market performance. All returns include the reinvestment of dividends and distributions. As always, please note that the Fund's past performance (before and after taxes) cannot predict how it will perform in the future. Updated performance information is available at no cost by visiting www.calamos.com or by calling 800.582.6959.

PROSPECTUS | March 1, 2023
25


Calamos Convertible Fund

CLASS I* ANNUAL TOTAL RETURN FOR YEARS ENDED 12.31

Highest Quarterly Return:

   

30.35

% (6.30.2020)

 

Lowest Quarterly Return:

   

-16.35

% (6.30.2022)

 

*  Annual returns for Class I are provided because Class I shares represent the largest percentage of assets in the Calamos Family of Funds.

Average Annual Total Returns as of 12.31.22

The following table shows how the Fund's average annual performance (before and after taxes) for the one-, five- and ten-year periods ended December 31, 2022 and since the Fund's inception compared with broad measures of market performance. "Since Inception" returns shown for each index are returns since the inception of the Fund's Class A shares, or since the nearest subsequent month end when comparative index data is available only for full monthly periods. The after-tax returns show the impact of assumed federal income taxes on an investment in the Fund. "Return After Taxes on Distributions" shows the effect of taxable distributions, but assumes that you still hold the Fund shares at the end of the period and so do not have any taxable gain or loss on your investment. "Return After Taxes on Distributions and Sale of Fund Shares" shows the effect of taxable distributions and any taxable gain or loss that would be realized if the Fund shares were purchased at the beginning and sold at the end of the specified period.

The after-tax returns are shown only for Class I shares, and are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes. Actual after-tax returns depend on an investor's tax situation and may differ from those shown, and the after-tax returns shown are not relevant to investors who hold their Fund shares through tax-advantaged arrangements, such as 401(k) plans or individual retirement accounts. After-tax returns for classes other than Class I will vary from returns shown for Class I. "Return After Taxes on Distributions and Sale of Fund Shares" may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of Fund shares.

CALAMOS FAMILY OF FUNDS
26


Calamos Convertible Fund

AVERAGE ANNUAL TOTAL RETURNS — FOR THE PERIODS ENDED 12.31.22

    INCEPTION
DATE OF CLASS
 

ONE YEAR

 

FIVE YEAR

 

TEN YEAR

  SINCE
INCEPTION
 

Class A

   

6.21.85

                   

Load Adjusted Return before taxes

       

-23.00

%

   

7.57

%

   

7.36

%

   

8.71

%

 

Class C

   

7.5.96

                   

Load Adjusted Return before taxes

       

-22.61

%

   

7.26

%

   

7.08

%

   

7.28

%

 

Class I

   

6.25.97

                   

Return before taxes

       

-21.03

%

   

8.32

%

   

8.16

%

   

7.73

%

 

Return after taxes on distributions*

       

-21.32

%

   

5.92

%

   

5.82

%

   

5.58

%

 
Return after taxes on distributions and sale of
Fund shares*
       

-12.44

%

   

6.12

%

   

5.85

%

   

5.65

%

 

ICE BofA All U.S. Convertibles Index (VXA0)

       

-18.71

%

   

9.29

%

   

10.01

%

   

7.84

%

 

S&P 500 Index

       

-18.11

%

   

9.42

%

   

12.56

%

   

7.91

%

 

*  Returns after taxes for Class I are provided because Class I shares represent the largest percentage of assets in the Calamos Family of Funds.

Since inception return for the ICE BofA All US Convertible Index is not available, as the inception date of the Index is January 1, 1988. The S&P 500 Index shows how the Fund's performance compares to an index that is generally considered to be representative of the U.S. stock market.

Investment Adviser

Calamos Advisors LLC

PORTFOLIO MANAGER/
FUND TITLE (IF APPLICABLE)
  PORTFOLIO MANAGER
EXPERIENCE IN THE FUND
  PRIMARY TITLE
WITH INVESTMENT ADVISER
 

John P. Calamos, Sr. (President, Chairman)

 

since Fund's inception

 

Founder, Chairman, and Global CIO

 

R. Matthew Freund

  6 years  

SVP, Sr. Co-Portfolio Manager

 

John Hillenbrand

  19 years  

SVP, Sr. Co-Portfolio Manager

 

Eli Pars

  9.5 years  

SVP, Sr. Co-Portfolio Manager

 

Jon Vacko

  19 years  

SVP, Sr. Co-Portfolio Manager

 

Joe Wysocki

  8 years  

SVP, Sr. Co-Portfolio Manager

 

Other Important Information Regarding Fund Shares

For important information about purchase and sale of Fund shares, tax information, and financial intermediary compensation, please turn to "Other Important Information Regarding Fund Shares" on page 115 of the prospectus.

PROSPECTUS | March 1, 2023
27


Calamos Global Convertible Fund

Investment Objective

Calamos Global Convertible Fund's primary objective is total return through capital appreciation and current income.

Fees and Expenses of the Fund

The following table describes the fees and expenses that you may pay if you buy, hold and sell shares of the Fund. Investors may pay other fees, such as brokerage commissions and/or other forms of compensation to a financial intermediary, which are not reflected in the tables or the examples below. You may qualify for sales charge discounts on purchases of Class A shares if you and your family invest, or agree to invest in the future, at least $100,000 in Calamos Funds. More information about these and other discounts is available from your financial professional and under "Fund Facts — What classes of shares do the Funds offer?" on page 138 of the Fund's prospectus, in the Appendix to this prospectus and "Share Classes and Pricing of Shares" on page 66 of the Fund's statement of additional information.

Shareholder Fees (fees paid directly from your investment):

   

CLASS A

 

CLASS C

 

CLASS I

 

Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price)

   

2.25

%

   

None

     

None

   
Maximum Deferred Sales Charge (Load) (as a percentage of the lesser of the redemption price or
offering price)
   

None

     

1.00

%

   

None

   

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment):

   

CLASS A

 

CLASS C

 

CLASS I

 

Management Fees

   

0.85

%

   

0.85

%

   

0.85

%

 

Distribution and/or Service Fees (12b-1)

   

0.25

%

   

1.00

%

   

None

   

Other Expenses

   

0.18

%

   

0.18

%

   

0.18

%

 

Total Annual Fund Operating Expenses

   

1.28

%

   

2.03

%

   

1.03

%

 

Example

This example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds. The example assumes that you invest $10,000 in the Fund for the time periods indicated and then either redeem or do not redeem your shares at the end of the reflected time periods. The example also assumes that your investment has a 5% return each year, that all dividends and capital gain distributions are reinvested, that you pay a maximum initial deferred sales charge and that the Fund's operating expenses remain the same. Although your actual performance and costs may be higher or lower, based on these assumptions, your costs would be:

You would pay the following expenses if you redeemed your shares at the end of the period:

   

One Year

 

Three Years

 

Five Years

 

Ten Years

 

Class A

   

352

     

622

     

911

     

1,735

   

Class C

   

306

     

637

     

1,093

     

2,358

   

Class I

   

105

     

328

     

569

     

1,259

   

You would pay the following expenses if you did not redeem your shares:

   

One Year

 

Three Years

 

Five Years

 

Ten Years

 

Class A

   

352

     

622

     

911

     

1,735

   

Class C

   

206

     

637

     

1,093

     

2,358

   

Class I

   

105

     

328

     

569

     

1,259

   

CALAMOS FAMILY OF FUNDS
28


Calamos Global Convertible Fund

Portfolio Turnover

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when Fund shares are held in a taxable account. These costs, which are not reflected in the annual fund operating expenses or in the example, affect the Fund's performance. During the Fund's most recent fiscal year the Fund's portfolio turnover rate was 31% of the average value of its portfolio.

Principal Investment Strategies

The Fund invests mainly in a globally-diversified portfolio of convertible securities (including synthetic convertible instruments) issued by both U.S. and foreign companies without regard to market capitalization. Convertible securities include, but are not limited to, any corporate debt security, debentures, notes or preferred stock that may be converted into equity securities of companies around the world, including in emerging markets. A synthetic convertible instrument is a financial instrument (or two or more securities held in tandem) that is designed to simulate the economic characteristics of a convertible security through the combined features of a debt instrument and a security providing an option on an equity security. Under normal circumstances, the Fund invests at least 80% of its net assets (plus borrowings for investment purposes, if any) in convertible securities, including synthetic convertible securities. The Fund may establish a synthetic convertible instrument by combining fixed-income securities (which may be either convertible or non-convertible) with the right to acquire equity securities. In establishing a synthetic instrument, the Fund may combine a basket of fixed-income securities with a basket of warrants or options that together produce economic characteristics similar to a convertible security. Within each basket of fixed-income securities and warrants or options, different companies may issue the fixed-income and convertible components, which may be purchased separately and at different times.

The Fund anticipates that, under normal circumstances, the investment adviser's process will result in the Fund investing in a globally diversified manner, with at least 20% of its assets in securities of foreign issuers, including issuers in emerging markets. Securities of foreign issuers are securities issues by issuers that are organized under the laws of a foreign country or that have a substantial portion of their operations or assets in a foreign country or countries, or that derive a substantial portion of their revenue or profits from businesses, investments or sales outside of the United States. The Fund may also invest in foreign securities that are represented in the United States securities markets by American Depositary Receipts ("ADRs") or similar depository arrangements. The Fund's foreign debt investments can be denominated in U.S. dollars or in foreign currencies. Debt securities issued by a foreign government may not be supported by the "full faith and credit" of that government.

The Fund may invest up to 20% of its net assets in equity securities or securities with economic characteristics similar to stock or the equity markets. The Fund may also invest up to 20% of its net assets in high yield fixed-income securities, often referred to as "junk bonds"; however, such limitation shall not apply to convertible securities, including synthetic convertible securities. Junk bonds are securities rated BB or lower by S&P, or Ba or lower by Moody's or securities that are not rated but are considered by the Fund's investment adviser to be of similar quality. The Fund may not acquire debt securities that are rated lower than C. In addition, the Fund may engage in active and frequent trading of portfolio securities.

The Fund may use derivative instruments such as options, futures and forward contracts. The Fund may purchase or sell securities on a when-issued, delayed delivery or forward commitment basis.

When buying and selling convertible securities, the Fund typically applies a four-step approach, without regard to market capitalization:

1. Evaluating the default risk of the convertible security using traditional credit analysis;

2. Analyzing the convertible security's underlying common stock to determine its capital appreciation potential;

3. Assessing the convertible security's risk/return potential; and

4. Evaluating the convertible security's impact on the Fund's overall composition and diversification strategy.

As well, the Fund's investment adviser seeks to lower the risks of investing in stocks by using a "top-down approach" of diversification by country, company, industry, sector and currency and by focusing on macro-level investment themes.

PROSPECTUS | March 1, 2023
29


Calamos Global Convertible Fund

Consistent with the Fund's investment objective and principal investment strategies the Fund's investment adviser views these strategies as low volatility equity strategies and attempts to achieve equity-like returns with lower than equity market risk by managing a portfolio that it believes will exhibit less volatility over full market cycles.

Principal Risks

An investment in the Fund is subject to risks, and you could lose money on your investment in the Fund. There can be no assurance that the Fund will achieve its investment objective. The risks associated with an investment in the Fund can increase during times of significant market volatility. Your investment in the Fund is not a deposit in a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency. The principal risks are presented in alphabetical order to facilitate finding particular risks and comparing them with other funds. Each risk summarized below is considered a "principal risk" of investing in the Fund, regardless of the order in which it appears. The principal risks of investing in the Fund include:

•  American Depositary Receipts Risk — The stocks of most foreign companies that trade in the U.S. markets are traded as American Depositary Receipts (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.

•  Convertible Securities Risk — The value of a convertible security is influenced by changes in interest rates, with investment value declining as interest rates increase and increasing as interest rates decline. The credit standing of the issuer and other factors also may have an effect on the convertible security's investment value. Convertible securities generally offer lower interest or dividend yields than non-convertible fixed-income securities of similar credit quality because of the potential for capital appreciation. In addition, as the market price of the underlying common stock declines below the conversion price, the price of the convertible security tends to be increasingly influenced by the yield of the convertible security. Holders of convertible securities have a claim on the issuer's assets prior to the common stockholders, but may be subordinated to holders of similar but non-convertible securities of the same issuer.

•  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.

•  Debt Securities Risk — Debt securities are subject to various risks, including interest rate risk, credit risk and default risk.

•  Interest Rate Risk — The value of debt securities generally decreases in periods when interest rates are rising. In addition, interest rate changes typically have a greater effect on prices of longer-term debt securities than shorter term debt securities. Recent fixed-income market events, including increases in volatility and interest rates, may expose the Fund to heightened interest rate risk and volatility.

•  Credit Risk — A debt security could deteriorate in quality to such an extent that its rating is downgraded or its market value declines relative to comparable securities. Changes in actual or perceived creditworthiness may occur quickly. If the Fund holds securities that have been downgraded, or that default on payment, the Fund's performance could be negatively affected.

•  Default Risk — A company that issues a debt security may be unable to fulfill its obligation to repay principal and interest. The lower a bond is rated, the greater its default risk. To the extent the Fund holds securities that have been downgraded, or that default on payment, its performance could be negatively affected.

•  Derivatives Risk — Derivatives are instruments, such as futures and forward foreign currency contracts, whose value is derived from that of other assets, rates or indices. The use of derivatives for non-hedging purposes may be considered more speculative than other types of investments. Derivatives can be used for hedging (attempting to reduce risk by

CALAMOS FAMILY OF FUNDS
30


Calamos Global Convertible Fund

offsetting one investment position with another) or non-hedging purposes. Hedging with derivatives may increase expenses, and there is no guarantee that a hedging strategy will work. While hedging can reduce or eliminate losses, it can also reduce or eliminate gains. In addition, derivative instruments are subject to counterparty risk, meaning that the party with whom the Fund enters into the derivatives contract may experience a significant credit event and/or may be unwilling or unable to make timely settlement payments or otherwise honor its obligations. Changes in the value of a derivative may not correlate perfectly with the underlying asset, rate or index, and the Fund could lose more than the principal amount invested.

•  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 hurt their economies and securities markets. Securities issued in these countries may be more volatile and less liquid than securities issued in foreign countries with more developed economies or markets. Loss may also result from the imposition of exchange controls, confiscations and other government restrictions, or from problems in share registration, settlement, custody, or other operational risks.

•  Equity Securities Risk — The securities markets are volatile, and the market prices of the Fund's securities may decline generally. The price of equity securities fluctuates based on changes in a company's financial condition and overall market and economic conditions. If the market prices of the securities owned by the Fund fall, the value of your investment in the Fund will decline.

•  Foreign Securities Risk — Risks associated with investing in foreign securities include fluctuations in the exchange rates of foreign currencies that may affect the U.S. dollar value of a security, the possibility of substantial price volatility as a result of political and economic instability in the foreign country, less public information about issuers of securities, different securities regulation, different accounting, auditing and financial reporting standards and less liquidity than in U.S. markets.

•  Forward Foreign Currency Contract Risk — Forward foreign currency 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 foreign currency 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 with whom the Fund enters into the derivatives contract (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.

•  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.

•  High Yield Risk — High yield securities and unrated securities of similar credit quality (commonly known as "junk bonds") are subject to greater levels of credit and liquidity risks. High yield securities are considered primarily speculative with respect to the issuer's continuing ability to make principal and interest payments.

•  Options Risk — The Fund's ability to close out its position as a purchaser or seller of an exchange-listed put or call option is dependent, in part, upon the liquidity of the options market. There are significant differences between the securities and options markets that could result in an imperfect correlation among these markets, causing a given transaction not to achieve its objectives. The Fund's ability to utilize options successfully will depend on the ability of the Fund's

PROSPECTUS | March 1, 2023
31


Calamos Global Convertible Fund

investment adviser to predict pertinent market movements, which cannot be assured. The Fund may also purchase or write over-the-counter put or call options, which involves risks different from, and possibly greater than, the risks associated with exchange-listed put or call options. In some instances, over-the-counter put or call options may expose the Fund to the risk that a counterparty may be unable or unwilling to perform according to a contract, and that any deterioration in a counterparty's creditworthiness could adversely affect the instrument. In addition, the Fund may be exposed to a risk that losses may exceed the amount originally invested.

•  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.

•  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.

•  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 of its board of trustees, the Fund 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.

•  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.

•  Securities Lending Risk — The Fund may lend its portfolio securities to broker-dealers and banks in order to generate additional income for the Fund. Any such loan must be continuously secured by collateral in cash or cash equivalents maintained on a current basis in an amount at least equal to the market value of the securities loaned by the Fund. In the event of bankruptcy or other default of a borrower of portfolio securities, the Fund could experience both delays in liquidating the loan collateral or recovering the loaned securities and losses, including (a) possible decline in the value of the collateral or in the value of the securities loaned during the period while the Fund seeks to enforce its rights thereto, (b) possible subnormal levels of income and lack of access to income during this period, and (c) expenses of enforcing its rights. In an effort to reduce these risks, the Fund's securities lending agent monitors, and reports to Calamos Advisors on, the creditworthiness of the firms to which a Fund lends securities. The Fund may also experience losses as a result of a diminution in value of its cash collateral investments.

•  Synthetic Convertible Instruments Risk — The value of a synthetic convertible instrument may respond differently to market fluctuations than a traditional convertible security because a synthetic convertible instrument is composed of two or more separate securities or instruments, each with its own market value. Because the convertible component is typically achieved by investing in warrants or options to buy common stock at a certain exercise price, or options on a stock index, synthetic convertible instruments are subject to the risks associated with derivatives. 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.

•  Tax Risk — The federal income tax treatment of convertible securities or other securities in which the Fund may invest may not be clear or may be subject to recharacterization by the Internal Revenue Service. It could be more difficult to comply with the tax requirements applicable to regulated investment companies if the tax characterization of investments or the tax treatment of the income from such investments were successfully challenged by the Internal Revenue Service. Any such failure to comply with the rules applicable to regulated investment companies could cause the Fund to fail to qualify as such.

CALAMOS FAMILY OF FUNDS
32


Calamos Global Convertible Fund

Fund Performance

The following bar chart and table indicate the risks of investing in the Fund by showing changes in the Fund's performance from calendar year to calendar year and how the Fund's average annual total returns compare with those of a broad measure of market performance. All returns include the reinvestment of dividends and distributions. As always, please note that the Fund's past performance (before and after taxes) cannot predict how it will perform in the future. Updated performance information is available at no cost by visiting www.calamos.com or by calling 800.582.6959.

CLASS I* ANNUAL TOTAL RETURN FOR YEARS ENDED 12.31

Highest Quarterly Return:

   

19.56

% (6.30.2020)

 

Lowest Quarterly Return:

   

-15.92

% (6.30.2022)

 

*  Annual returns for Class I are provided because Class I shares represent the largest percentage of assets in the Calamos Family of Funds.

Average Annual Total Returns as of 12.31.22

The following table shows how the Fund's average annual performance (before and after taxes) for the one- and five- year periods ended December 31, 2022 and since the Fund's inception compared with broad measures of market performance. "Since Inception" returns shown for the index are returns since the inception of the Fund's Class A shares, or since the nearest subsequent month end when comparative index data is available only for full monthly periods. The after-tax returns show the impact of assumed federal income taxes on an investment in the Fund. "Return After Taxes on Distributions" shows the effect of taxable distributions, but assumes that you still hold the Fund shares at the end of the period and so do not have any taxable gain or loss on your investment. "Return After Taxes on Distributions and Sale of Fund Shares" shows the effect of taxable distributions and any taxable gain or loss that would be realized if the Fund shares were purchased at the beginning and sold at the end of the specified period.

The after-tax returns are shown only for Class I shares, and are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes. Actual after-tax returns depend on an investor's tax situation and may differ from those shown, and the after-tax returns shown are not relevant to investors who hold their Fund shares through tax-advantaged arrangements, such as 401(k) plans or individual retirement accounts. After-tax returns for classes other than Class I will vary from returns shown for Class I. "Return After Taxes on Distributions and Sale of Fund Shares" may be higher than other returns for the same period due to a tax benefit of realizing a capital loss on the sale of Fund shares.

PROSPECTUS | March 1, 2023
33


Calamos Global Convertible Fund

AVERAGE ANNUAL TOTAL RETURNS — FOR THE PERIODS ENDED 12.31.22

    INCEPTION
DATE OF CLASS
 

ONE YEAR

 

FIVE YEAR

  SINCE
INCEPTION
 

Class A

   

12.31.14

               

Load Adjusted Return before taxes

       

-23.98

%

   

3.11

%

   

3.55

%

 

Class C

   

12.31.14

               

Load Adjusted Return before taxes

       

-23.61

%

   

2.79

%

   

3.41

%

 

Class I

   

12.31.14

               

Return before taxes

       

-22.06

%

   

3.84

%

   

4.45

%

 

Return after taxes on distributions*

       

-22.06

%

   

1.91

%

   

2.93

%

 

Return after taxes on distributions and sale of Fund shares*

       

-13.06

%

   

2.61

%

   

3.15

%

 

Refinitiv Global Convertible Bond Index

       

-18.88

%

   

4.42

%

   

4.47

%

 

*  Returns after taxes for Class I are provided because Class I shares represent the largest percentage of assets in the Calamos Family of Funds.

Investment Adviser

Calamos Advisors LLC

PORTFOLIO MANAGER/
FUND TITLE (IF APPLICABLE)
  PORTFOLIO MANAGER
EXPERIENCE IN THE FUND
  PRIMARY TITLE
WITH INVESTMENT ADVISER
 

John P. Calamos, Sr. (President, Chairman)

 

since Fund's inception

 

Founder, Chairman, and Global CIO

 

R. Matthew Freund

  6 years  

SVP, Sr. Co-Portfolio Manager

 

John Hillenbrand

 

since Fund's inception

 

SVP, Sr. Co-Portfolio Manager

 

Nick Niziolek

 

since Fund's inception

 

SVP, Sr. Co-Portfolio Manager

 

Eli Pars

 

since Fund's inception

 

SVP, Sr. Co-Portfolio Manager

 

Dennis Cogan

 

since Fund's inception

 

SVP, Sr. Co-Portfolio Manager

 

Jon Vacko

 

since Fund's inception

 

SVP, Sr. Co-Portfolio Manager

 

Joe Wysocki

  8 years  

SVP, Sr. Co-Portfolio Manager

 

Anthony Vecchiolla

 

since February 2023

 

VP, Co-Portfolio Manager

 

Other Important Information Regarding Fund Shares

For important information about purchase and sale of Fund shares, tax information, and financial intermediary compensation, please turn to "Other Important Information Regarding Fund Shares" on page 115 of the prospectus.

CALAMOS FAMILY OF FUNDS
34


Calamos Timpani Small Cap Growth Fund

Investment Objective

Calamos Timpani Small Cap Growth Fund's investment objective is capital appreciation.

Fees and Expenses of the Fund

The following table describes the fees and expenses that you may pay if you buy, hold and sell shares of the Fund. Investors may pay other fees, such as brokerage commissions and/or other forms of compensation to a financial intermediary, which are not reflected in the tables or the examples below. You may qualify for sales charge discounts on purchases of Class A shares if you and your family invest, or agree to invest in the future, at least $50,000 in Calamos Funds. More information about these and other discounts is available from your financial professional and under "Fund Facts — What classes of shares do the Funds offer?" on page 138 of the Fund's prospectus, in the Appendix to this prospectus and "Share Classes and Pricing of Shares" on page 66 of the Fund's statement of additional information.

Shareholder Fees (fees paid directly from your investment):

   

CLASS A

 

CLASS C

 

CLASS I

 

CLASS R6

 
Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of
offering price)
   

4.75

%

   

None

     

None

     

None

   
Maximum Deferred Sales Charge (Load) (as a percentage of the lesser of the
redemption price or offering price)
   

None

     

1.00

%

   

None

     

None

   

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment):

   

CLASS A

 

CLASS C

 

CLASS I

 

CLASS R6

 

Management Fees

   

0.90

%

   

0.90

%

   

0.90

%

   

0.90

%

 

Distribution and/or Service Fees (12b-1)

   

0.25

%

   

1.00

%

   

None

     

None

   

Other Expenses

   

0.22

%

   

0.22

%

   

0.22

%

   

0.10

%

 

Total Annual Fund Operating Expenses

   

1.37

%

   

2.12

%

   

1.12

%

   

1.00

%

 

Expense Reimbursement1

   

(0.07

)%

   

(0.07

)%

   

(0.07

)%

   

(0.07

)%

 

Total Annual Fund Operating Expenses After Reimbursement

   

1.30

%

   

2.05

%

   

1.05

%

   

0.93

%

 

1  The Fund's investment advisor has contractually agreed to reimburse Fund expenses through March 1, 2024 to the extent necessary so that Total Annual Fund Operating Expenses of Class A shares, Class C and Class I shares are limited to 1.30%, 2.05% and 1.05% of average net assets, respectively. The Fund's investment advisor has contractually agreed to limit the Fund's annual ordinary operating expenses through March 1, 2024 for Class R6 shares (as a percentage of average net assets) to 1.05% less the Fund's annual sub-transfer agency ratio (the aggregate sub-transfer agency fees of the Fund's other share classes divided by the aggregate average annual net assets of the Fund's other share classes). For purposes of these expense limitations, operating expenses do not include taxes, interest, short interest, short dividend expenses, brokerage commissions, acquired fund fees and expenses, and extraordinary expenses, if any. Calamos Advisors LLC ("Calamos Advisors") may recapture previously waived expense amounts within the same fiscal year for any day where the respective share class's expense ratio falls below the contractual expense limit up to the expense limit for that day. This undertaking is binding on Calamos Advisors and any of its successors and assigns. This agreement is not terminable by either party.

Example

This example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds. The example assumes that you invest $10,000 in the Fund for the time periods indicated and then either redeem or do not redeem your shares at the end of the reflected time periods. The example also assumes that your investment has a 5% return each year that all dividends and capital gain distributions are reinvested, that you pay a maximum initial or contingent deferred sales charge and that the Fund's operating expenses remain the same. Any applicable fee waivers and/or expense

PROSPECTUS | March 1, 2023
35


Calamos Timpani Small Cap Growth Fund

reimbursements are reflected in the below examples for the period through March 1, 2024 only. Although your actual performance and costs may be higher or lower, based on these assumptions, your costs would be:

You would pay the following expenses if you redeemed your shares at the end of the period:

   

One Year

 

Three Years

 

Five Years

 

Ten Years

 

Class A

   

601

     

882

     

1,183

     

2,037

   

Class C

   

308

     

657

     

1,133

     

2,446

   

Class I

   

107

     

349

     

610

     

1,357

   

Class R6

   

95

     

311

     

546

     

1,218

   

You would pay the following expenses if you did not redeem your shares at the end of the period:

   

One Year

 

Three Years

 

Five Years

 

Ten Years

 

Class A

   

601

     

882

     

1,183

     

2,037

   

Class C

   

208

     

657

     

1,133

     

2,446

   

Class I

   

107

     

349

     

610

     

1,357

   

Class R6

   

95

     

311

     

546

     

1,218

   

Portfolio Turnover

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when Fund shares are held in a taxable account. These costs, which are not reflected in the annual fund operating expenses or in the example, affect the Fund's performance. During the Fund's most recent fiscal year the Fund's portfolio turnover rate was 197% of the average value of its portfolio.

Principal Investment Strategies

Under normal market conditions, the Fund invests at least 80% of its net assets (plus any borrowings) in equity securities of small capitalization companies that the Fund's investment adviser, Calamos Advisors LLC ("Calamos Advisors"), believes have sound growth potential. The Fund defines a small capitalization company as any company with a market capitalization less than or equal to that of the company with the largest market capitalization of either the Russell 2000® Index or the MSCI USA Small Cap Index as measured on a rolling 24-month basis over the most recent period. The market capitalization of a security is measured at the time of purchase.

Equity securities in which the Fund invests as a part of its principal investment strategy consist of common stocks and American Depositary Receipts ("ADRs"). The Fund may invest up to 25% of its net assets in foreign securities. Foreign securities are securities issued by issuers that are organized under the laws of a foreign country, that have a substantial portion of their operations or assets in a foreign country or countries, or that derive a substantial portion of their revenue or profits from businesses, investments, or sales outside of the United States. The Fund may also invest in foreign securities that are represented in the United States securities markets by ADRs or similar depositary arrangements. The Fund's foreign investments can be denominated in U.S. dollars or in foreign currencies. Calamos Advisors uses fundamental research to evaluate investment opportunities, focusing on companies that it believes have superior management and whose business models have a high potential for earnings upside. Calamos Advisors may actively trade portfolio securities. Currently, the Fund has significant investments in the healthcare and technology sectors due to Calamos Advisors' investment process yielding opportunities for sound growth potential within those sectors. However, the Fund is actively managed, and its portfolio may change in the future.

CALAMOS FAMILY OF FUNDS
36


Calamos Timpani Small Cap Growth Fund

Principal Risks

An investment in the Fund is subject to risks, and you could lose money on your investment in the Fund. There can be no assurance that the Fund will achieve its investment objective. The risks associated with an investment in the Fund can increase during times of significant market volatility. Your investment in the Fund is not a deposit in a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency. The principal risks are presented in alphabetical order to facilitate finding particular risks and comparing them with other funds. Each risk summarized below is considered a "principal risk" of investing in the Fund, regardless of the order in which it appears. The principal risks of investing in the Fund include:

•  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.

•  Cash Holdings Risk — The Fund may invest in cash and cash equivalents for indefinite periods of time when the Fund's investment adviser determines the prevailing market environment warrants doing so. When the Fund holds cash positions, it may lose opportunities to participate in market appreciation, which may result in lower returns than if the Fund had remained fully invested in the market. Furthermore, cash and cash equivalents may generate minimal or no income and could negatively impact the Fund's performance and ability to achieve its investment objective.

•  Equity Securities Risk — The securities markets are volatile, and the market prices of the Fund's securities may decline generally. The price of equity securities fluctuates based on changes in a company's financial condition and overall market and economic conditions. If the market prices of the securities owned by the Fund fall, the value of your investment in the Fund will decline.

•  Foreign Securities Risk — Risks associated with investing in foreign securities include fluctuations in the exchange rates of foreign currencies that may affect the U.S. dollar value of a security, the possibility of substantial price volatility as a result of political and economic instability in the foreign country, less public information about issuers of securities, different securities regulation, different accounting, auditing and financial reporting standards and less liquidity than in U.S. markets.

•  Growth Stock Risk — Growth securities typically trade at higher multiples of current earnings than other securities and, therefore, may be more sensitive to changes in current or expected earnings than other equity securities and may be more volatile.

•  Liquidity Risk — Liquidity risk exists when particular investments are difficult to purchase or sell. The Fund's investments in illiquid securities may reduce the returns of the Fund because it may be unable to sell the illiquid securities at an advantageous time or price.

•  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.

•  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.

•  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.

PROSPECTUS | March 1, 2023
37


Calamos Timpani Small Cap Growth Fund

•  Small Company Risk — Small company stocks have historically been subject to greater investment risk than mid and large company stocks. The prices of small company stocks tend to be more volatile than prices of mid and large company stocks.

Fund Performance

The following bar chart and table indicate the risks of investing in the Fund by showing changes in the Fund's performance from calendar year to calendar year and how the Fund's average annual total returns compare with those of a broad measure of market performance. All returns include the reinvestment of dividends and distributions. The performance shown in the bar chart and performance table for the period May 31, 2019 through December 31, 2022 is the Fund's performance whereas performance prior to May 31, 2019 is that of another investment vehicle (the "Predecessor Fund") prior to the commencement of the Fund's operations. On May 31, 2019, the Fund acquired all of the assets, subject to the liabilities, of the Predecessor Fund through a tax-free reorganization (the "Reorganization"). As a result of the Reorganization, the Fund adopted the performance and financial history of the Predecessor Fund. The Fund has the same investment objective, strategy and portfolio manager as the Predecessor Fund. As a result, the performance of the Fund would have been substantially similar to that of the Predecessor Fund.

The bar chart shows the performance of the Predecessor Fund's Institutional Class performance which was adopted by the Class I shares of the Fund for periods prior to the Reorganization. If the Predecessor Fund's investment adviser had not waived or reimbursed certain Predecessor Fund expenses during these periods, the Predecessor Fund's returns would have been lower. As always, please note that the Fund's past performance (before and after taxes) cannot predict how it will perform in the future. Updated performance information is available at no cost by visiting www.calamos.com or by calling 800.582.6959.

CLASS I* ANNUAL TOTAL RETURN FOR YEARS ENDED 12.31

Highest Quarterly Return:

   

40.93

% (6.30.2020)

 

Lowest Quarterly Return:

   

-23.99

% (6.30.2022)

 

*  Annual returns for Class I are provided because Class I shares represent the largest percentage of assets in the Calamos Family of Funds.

Average Annual Total Returns as of 12.31.22

The following table shows how the Fund's average annual performance (before and after taxes) for the one- and five-year periods ended December 31, 2022 and since the Fund's inception compared with broad measures of market performance. For periods prior to the Reorganization, the average annual total return table compares the Predecessor Fund's Institutional Class performance which was adopted by the Class I shares of the Fund and Class Y performance which was adopted by the Class A shares of the Fund and adjusted to reflect the maximum sales load of 4.75% for Class A shares, to that of the Russell 2000 Growth Index. "Since Inception" return shown for the Russell 2000 Growth Index is the return since the inception of the Predecessor Fund's Class Y shares. The after-tax returns show the impact of assumed federal income taxes on an investment in the Fund. "Return After Taxes on Distributions" shows the effect of taxable distributions, but assumes that you still hold the Fund shares at the end of the period and so do not have any taxable gain or loss on your investment. "Return After Taxes on Distributions and Sale of Fund Shares" shows the effect of taxable distributions and any taxable gain or loss that would be realized if the Fund shares were purchased at the beginning and sold at the end of the specified period.

CALAMOS FAMILY OF FUNDS
38


Calamos Timpani Small Cap Growth Fund

The after-tax returns are shown only for Class I shares, and are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes. Actual after-tax returns depend on an investor's tax situation and may differ from those shown, and the after-tax returns shown are not relevant to investors who hold their Fund shares through tax-advantaged arrangements, such as 401(k) plans or individual retirement accounts. After-tax returns for classes other than Class I shares will vary from returns shown for Class I shares. "Return After Taxes on Distributions and Sale of Fund Shares" may be higher than other returns for the same period due to a tax benefit of realizing a capital loss on the sale of Fund shares.

AVERAGE ANNUAL TOTAL RETURNS — FOR THE PERIODS ENDED 12.31.22

    INCEPTION
DATE OF CLASS
 

ONE YEAR

 

FIVE YEAR

 

TEN YEAR

  SINCE
INCEPTION
 

Class A

   

01.06.14

                   

Load Adjusted Return before taxes

       

-40.44

%

   

4.79

%

   

N/A

     

5.64

%

 

Class C

   

06.25.21

                   

Load Adjusted Return before taxes

       

-38.56

%

   

N/A

     

N/A

     

-29.94

%

 

Class I

   

03.23.11

                   

Return before taxes

       

-37.30

%

   

6.14

%

   

10.68

%

   

9.65

%

 

Return after taxes on distributions*

       

-37.30

%

   

5.38

%

   

10.21

%

   

9.26

%

 
Return after taxes on distributions and sale of
Fund shares*
       

-22.08

%

   

4.78

%

   

8.82

%

   

8.02

%

 

Class R6

   

05.31.19

                   

Load Adjusted Return before taxes

       

-37.24

%

   

N/A

     

N/A

     

4.70

%

 

Russell 2000 Growth Index

       

-26.36

%

   

3.51

%

   

9.20

%

   

7.94

%

 

*  Returns after taxes for Class I are provided because Class I shares represent the largest percentage of assets in the Calamos Family of Funds.

Investment Adviser

Calamos Advisors LLC

PORTFOLIO MANAGER/
FUND TITLE (IF APPLICABLE)
  PORTFOLIO MANAGER
EXPERIENCE IN THE FUND
  PRIMARY TITLE
WITH INVESTMENT ADVISER
 

Brandon Nelson

 

since Fund's inception

 

Senior Portfolio Manager

 

Other Important Information Regarding Fund Shares

For important information about purchase and sale of Fund shares, tax information, and financial intermediary compensation, please turn to "Other Important Information Regarding Fund Shares" on page 115 of the prospectus.

PROSPECTUS | March 1, 2023
39


Calamos Timpani SMID Growth Fund

Investment Objective

Calamos Timpani SMID Growth Fund's investment objective is capital appreciation.

Fees and Expenses of the Fund

The following table describes the fees and expenses that you may pay if you buy, hold and sell shares of the Fund. Investors may pay other fees, such as brokerage commissions and/or other forms of compensation to a financial intermediary, which are not reflected in the tables or the examples below. You may qualify for sales charge discounts on purchases of Class A shares if you and your family invest, or agree to invest in the future, at least $50,000 in Calamos Funds. More information about these and other discounts is available from your financial professional and under "Fund Facts — What classes of shares do the Funds offer?" on page 138 of the Fund's prospectus, in the Appendix to this prospectus and "Share Classes and Pricing of Shares" on page 66 of the Fund's statement of additional information.

Shareholder Fees (fees paid directly from your investment):

   

CLASS A

 

CLASS I

 

CLASS R6

 

Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price)

   

4.75

%

   

None

     

None

   
Maximum Deferred Sales Charge (Load) (as a percentage of the lesser of the redemption price or
offering price)
   

None

     

None

     

None

   

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment):

   

CLASS A

 

CLASS I

 

CLASS R6

 

Management Fees

   

0.95

%

   

0.95

%

   

0.95

%

 

Distribution and/or Service Fees (12b-1)

   

0.25

%

   

None

     

None

   

Other Expenses

   

0.73

%

   

0.70

%

   

0.68

%

 

Total Annual Fund Operating Expenses

   

1.93

%

   

1.65

%

   

1.63

%

 

Expense Reimbursement1

   

(0.58

)%

   

(0.55

)%

   

(0.56

)%

 

Total Annual Fund Operating Expenses After Reimbursement

   

1.35

%

   

1.10

%

   

1.07

%

 

1  The Fund's investment advisor has contractually agreed to reimburse Fund expenses through March 1, 2024 to the extent necessary so that Total Annual Fund Operating Expenses of Class A shares and Class I shares are limited to 1.35% and 1.10% of average net assets, respectively. The Fund's investment advisor has contractually agreed to limit the Fund's annual ordinary operating expenses through March 1, 2024 for Class R6 shares (as a percentage of average net assets) to 1.10% less the Fund's annual sub-transfer agency ratio (the aggregate sub-transfer agency fees of the Fund's other share classes divided by the aggregate average annual net assets of the Fund's other share classes). For purposes of these expense limitations, operating expenses do not include taxes, interest, short interest, short dividend expenses, brokerage commissions, acquired fund fees and expenses, and extraordinary expenses, if any. Calamos Advisors LLC ("Calamos Advisors") may recapture previously waived expense amounts within the same fiscal year for any day where the respective share class's expense ratio falls below the contractual expense limit up to the expense limit for that day. This undertaking is binding on Calamos Advisors and any of its successors and assigns. This agreement is not terminable by either party.

Example

This example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds. The example assumes that you invest $10,000 in the Fund for the time periods indicated and then either redeem or do not redeem your shares at the end of the reflected time periods. The example also assumes that your investment has a 5% return each year, that all dividends and capital gain distributions are reinvested, that you pay a maximum initial or contingent deferred sales charge and that the Fund's operating expenses remain the same. Any applicable fee waivers and/or expense

CALAMOS FAMILY OF FUNDS
40


Calamos Timpani SMID Growth Fund

reimbursements are reflected in the below examples for the period through March 1, 2024 only. Although your actual performance and costs may be higher or lower, based on these assumptions, your costs would be:

You would pay the following expenses whether or not you redeemed your shares at the end of the period:

   

One Year

 

Three Years

 

Five Years

 

Ten Years

 

Class A

   

606

     

998

     

1,416

     

2,577

   

Class I

   

112

     

466

     

845

     

1,908

   

Class R6

   

109

     

459

     

833

     

1,885

   

Portfolio Turnover

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when Fund shares are held in a taxable account. These costs, which are not reflected in the annual fund operating expenses or in the example, affect the Fund's performance. During the most recent fiscal year, the Fund's portfolio turnover rate was 205% of the average value of its portfolio.

Principal Investment Strategies

Under normal market conditions, the Fund invests at least 80% of its net assets (plus any borrowings) in equity securities of small and mid-capitalization ("SMID") companies of issuers primarily located in the United States. The Fund defines a SMID company as a company with a market capitalization less than or equal to that of the company with the largest market capitalization of the Russell 2500® Index or the MSCI USA SMID Cap Index as measured on a rolling 24-month basis over the most recent period. The market capitalization of a security is measured at the time of purchase.

Equity securities in which the Fund invests as a part of its principal investment strategy consist of common stocks and American Depositary Receipts ("ADRs"). The Fund may invest up to 25% of its net assets in foreign securities. Foreign securities are securities issued by issuers that are organized under the laws of a foreign country, that have a substantial portion of their operations or assets in a foreign country or countries, or that derive a substantial portion of their revenue or profits from businesses, investments or sales outside of the United States. The Fund may also invest in foreign securities that are represented in the United States securities markets by ADRs or similar depositary arrangements. The Fund's foreign investments can be denominated in U.S. dollars or in foreign currencies. Calamos Advisors uses fundamental research to evaluate investment opportunities, focusing on companies that it believes have superior management and whose business models have a high potential for earnings upside. Calamos Advisors may actively trade portfolio securities. From time to time, the Fund may have significant investments in certain sectors due to Calamos Advisors' investment process yielding opportunities for sound growth potential within those sectors. The Fund's sector concentrations may vary.

Principal Risks

An investment in the Fund is subject to risks, and you could lose money on your investment in the Fund. There can be no assurance that the Fund will achieve its investment objective. The risks associated with an investment in the Fund can increase during times of significant market volatility. Your investment in the Fund is not a deposit in a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency. The principal risks are presented in alphabetical order to facilitate finding particular risks and comparing them with other funds. Each risk summarized below is considered a "principal risk" of investing in the Fund, regardless of the order in which it appears. The principal risks of investing in the Fund include:

•  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.

PROSPECTUS | March 1, 2023
41


Calamos Timpani SMID Growth Fund

•  Cash Holdings Risk — The Fund may invest in cash and cash equivalents for indefinite periods of time when the Fund's investment adviser determines the prevailing market environment warrants doing so. When the Fund holds cash positions, it may lose opportunities to participate in market appreciation, which may result in lower returns than if the Fund had remained fully invested in the market. Furthermore, cash and cash equivalents may generate minimal or no income and could negatively impact the Fund's performance and ability to achieve its investment objective.

•  Equity Securities Risk — The securities markets are volatile, and the market prices of the Fund's securities may decline generally. The price of equity securities fluctuates based on changes in a company's financial condition and overall market and economic conditions. If the market prices of the securities owned by the Fund fall, the value of your investment in the Fund will decline.

•  Foreign Securities Risk — Risks associated with investing in foreign securities include fluctuations in the exchange rates of foreign currencies that may affect the U.S. dollar value of a security, the possibility of substantial price volatility as a result of political and economic instability in the foreign country, less public information about issuers of securities, different securities regulation, different accounting, auditing and financial reporting standards and less liquidity than in U.S. markets.

•  Growth Stock Risk — Growth securities typically trade at higher multiples of current earnings than other securities and, therefore, may be more sensitive to changes in current or expected earnings than other equity securities and may be more volatile.

•  Liquidity Risk — Liquidity risk exists when particular investments are difficult to purchase or sell. The Fund's investments in illiquid securities may reduce the returns of the Fund because it may be unable to sell the illiquid securities at an advantageous time or price.

•  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.

•  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.

•  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.

•  Small and Mid-Sized Company Stock Risk — Small to mid-sized company stocks have historically been subject to greater investment risk than large company stocks. The prices of small to mid-sized company stocks tend to be more volatile and less liquid than large company stocks. Small and mid-sized companies may have no or relatively short operating histories, or be newly formed public companies. Some of these companies have aggressive capital structures, including high debt levels, or are involved in rapidly growing or changing industries and/or new technologies, which pose additional risks.

CALAMOS FAMILY OF FUNDS
42


Calamos Timpani SMID Growth Fund

Fund Performance

The following bar chart and table indicate the risks of investing in the Fund by showing changes in the Fund's first full calendar year of performance compared to a broad measure of market performance. All returns include the reinvestment of dividends and distributions. As always, please note that the Fund's past performance (before and after taxes) cannot predict how it will perform in the future. Updated performance information is available at no cost by visiting www.calamos.com or by calling 800.582.6959.

CLASS I* ANNUAL TOTAL RETURN FOR YEARS ENDED 12.31

Highest Quarterly Return:

   

37.58

% (6.30.2020)

 

Lowest Quarterly Return:

   

-22.94

% (6.30.2022)

 

*  Annual returns for Class I are provided because Class I shares represent the largest percentage of assets in the Calamos Family of Funds.

Average Annual Total Returns as of 12.31.22

The following table shows how the Fund's average annual performance (before and after taxes) for the one-year period ended December 31, 2022 and since the Fund's inception compared with broad measures of market performance. "Since Inception" returns shown for each index are returns since the inception of the Fund's Class A shares, or since the nearest subsequent month end when comparative index data is available only for full monthly periods. The after-tax returns show the impact of assumed federal income taxes on an investment in the Fund. "Return After Taxes on Distributions" shows the effect of taxable distributions, but assumes that you still hold the Fund shares at the end of the period and so do not have any taxable gain or loss on your investment. "Return After Taxes on Distributions and Sale of Fund Shares" shows the effect of taxable distributions and any taxable gain or loss that would be realized if the Fund shares were purchased at the beginning and sold at the end of the specified period.

The after-tax returns are shown only for Class I shares and are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes. Actual after-tax returns depend on an investor's tax situation and may differ from those shown, and the after-tax returns shown are not relevant to investors who hold their Fund shares through tax-advantaged arrangements, such as 401(k) plans or individual retirement accounts. After-tax returns for classes other than Class I will vary from returns shown for Class I. "Return After Taxes on Distributions and Sale of Fund Shares" may be higher than other returns for the same period due to a tax benefit of realizing a capital loss on the sale of Fund shares.

PROSPECTUS | March 1, 2023
43


Calamos Timpani SMID Growth Fund

AVERAGE ANNUAL TOTAL RETURNS — FOR THE PERIODS ENDED 12.31.22

    INCEPTION
DATE OF CLASS
 

ONE YEAR

  SINCE
INCEPTION
 

Class A

   

7.31.19

           

Load Adjusted Return before taxes

       

-38.11

%

   

0.42

%

 

Class I

   

7.31.19

           

Return before taxes

       

-34.88

%

   

2.12

%

 

Return after taxes on distributions*

       

-34.88

%

   

1.24

%

 

Return after taxes on distributions and sale of Fund shares*

       

-20.65

%

   

1.81

%

 

Class R6

   

7.31.19

           

Load Adjusted Return before taxes

       

-34.77

%

   

2.15

%

 

Russell 2500 Growth Index

       

-26.21

%

   

4.11

%

 

*  Returns after taxes for Class I are provided because Class I shares represent the largest percentage of assets in the Calamos Family of Funds.

Investment Adviser

Calamos Advisors LLC

PORTFOLIO MANAGER/
FUND TITLE (IF APPLICABLE)
  PORTFOLIO MANAGER
EXPERIENCE IN THE FUND
  PRIMARY TITLE
WITH INVESTMENT ADVISER
 

Brandon Nelson

 

since Fund's inception

 

Senior Portfolio Manager

 

Ryan Isherwood

 

since Fund's inception

 

Co-Portfolio Manager

 

Other Important Information Regarding Fund Shares

For important information about purchase and sale of Fund shares, tax information, and financial intermediary compensation, please turn to "Other Important Information Regarding Fund Shares" on page 115 of the prospectus.

CALAMOS FAMILY OF FUNDS
44


Calamos Growth Fund

Investment Objective

Calamos Growth Fund's investment objective is long-term capital growth.

Fees and Expenses of the Fund

The following table describes the fees and expenses that you may pay if you buy, hold and sell shares of the Fund. Investors may pay other fees, such as brokerage commissions and/or other forms of compensation to a financial intermediary, which are not reflected in the tables or the examples below. You may qualify for sales charge discounts on purchases of Class A if you and your family invest, or agree to invest in the future, at least $50,000 in Calamos Funds. More information about these and other discounts is available from your financial professional and under "Fund Facts — What classes of shares do the Funds offer?" on page 138 of the Fund's prospectus, in the Appendix to this prospectus and "Share Classes and Pricing of Shares" on page 66 of the Fund's statement of additional information.

Shareholder Fees (fees paid directly from your investment):

   

CLASS A

 

CLASS C

 

CLASS I

 

Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price)

   

4.75

%

   

None

     

None

   
Maximum Deferred Sales Charge (Load) (as a percentage of the lesser of the redemption price or
offering price)
   

None

     

1.00

%

   

None

   

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment):

   

CLASS A

 

CLASS C

 

CLASS I

 

Management Fees

   

0.90

%

   

0.90

%

   

0.90

%

 

Distribution and/or Service Fees (12b-1)

   

0.25

%

   

1.00

%

   

None

   

Other Expenses

   

0.15

%

   

0.15

%

   

0.15

%

 

Total Annual Fund Operating Expenses

   

1.30

%

   

2.05

%

   

1.05

%

 

Example

This example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds. The example assumes that you invest $10,000 in the Fund for the time periods indicated and then either redeem or do not redeem your shares at the end of the reflected time periods. The example also assumes that your investment has a 5% return each year, that all dividends and capital gain distributions are reinvested, that you pay a maximum initial or contingent deferred sales charge and that the Fund's operating expenses remain the same. Although your actual performance and costs may be higher or lower, based on these assumptions, your costs would be:

You would pay the following expenses if you redeemed your shares at the end of the period:

   

One Year

 

Three Years

 

Five Years

 

Ten Years

 

Class A

   

601

     

868

     

1,154

     

1,968

   

Class C

   

308

     

643

     

1,103

     

2,379

   

Class I

   

107

     

334

     

579

     

1,283

   

You would pay the following expenses if you did not redeem your shares:

   

One Year

 

Three Years

 

Five Years

 

Ten Years

 

Class A

   

601

     

868

     

1,154

     

1,968

   

Class C