(1)            Represents the estimated commission with respect to the Fund’s common shares being sold in this offering. There is no guarantee that there will be any sales of the Fund’s common shares pursuant to this prospectus supplement and the accompanying prospectus. Actual sales of the Fund’s common shares under this prospectus supplement and the accompanying prospectus, if any, may be less than as set forth under “Capitalization” above. In addition, the price per share of any such sale may be greater or less than the price set forth under “Capitalization” above, depending on the market price of the Fund’s common shares at the time of any such sale.

 

(2)            Shareholders will pay a $15.00 transaction fee plus a $0.02 per share brokerage charge if they direct Computershare Shareowner Services LLC (the “Plan Agent”) to sell common shares held in an account of the Fund’s Automatic Dividend Reinvestment Plan (the “Plan”). In addition, each participant will pay a pro rata share of brokerage commissions incurred with respect to the Plan Agent’s open-market purchases in connection with the reinvestment of dividends or distributions. If a participant elects to have the Plan Agent sell part or all of his or her common shares and remit the proceeds, such participant will be charged his or her pro rata share of brokerage commissions on the shares sold. See “Dividends and Distributions on Common Shares; Automatic Dividend Reinvestment Plan” on page 74 of the accompanying prospectus.

 

(7)            The example includes sales load and estimated offering costs.

The section titled “Effects of Leverage” beginning on page 40 of the Prospectus is deleted in its entirety and replaced with the following:

 

The SSB Agreement provides for credit availability for the Fund, such that it may borrow up to $480 million. As of August 26, 2026, the Fund had utilized $369.4 million of the $480 million available under the SSB Agreement ($125.6 million in borrowings outstanding, and $243.8 million in structural leverage consisting of collateral received from SSB in connection with securities on loan), representing 24.3% of the Fund’s managed assets as of that date, and had $124 million of MRP Shares outstanding, representing 8.2% of the Fund’s managed assets. Combined, the borrowings under the SSB Agreement and the outstanding MRP Shares represented 32.5% of the Fund’s managed assets. Interest on the SSB Agreement is charged on the drawn amount at the rate of the Overnight Bank Financing Rate (“OBFR”) plus 0.52%, payable monthly in arrears. Interest on overdue amounts or interest on the drawn amount paid during an event of default will be charged at OBFR plus 2.52%. These rates represent floating rates of interest that may change over time. The SSB Agreement has a commitment fee of 0.10% of any undrawn amount. As of August 26, 2026, the interest rate charged under the SSB Agreement was 4.19%.

 

The Fund’s MRP Shareholders are entitled to receive monthly cash dividends, at a currently effective dividend rate per annum for each series of MRP Shares as follows (subject to adjustment as described above in “Mandatory Redeemable Preferred Shares”): 4.24% for Series C MRP Shares, 2.68% for Series E MRP Shares, 6.24% for Series G MRP Shares, and 6.19% for Series H MRP Shares.

 

To cover the interest expense on the borrowings under the SSB Agreement (including “net income” payments made with respect to borrowings offset by collateral for securities on loan) and the dividend payments associated with the MRP Shares, based on rates in effect on August 26, 2026, the Fund’s portfolio would need to experience an annual return of 1.33% (before giving effect to expenses associated with senior securities).

 

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

 

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

 

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

 

Because Calamos’ investment management fee is a percentage of the Fund’s managed assets, Calamos’ fee will be higher if the Fund is leveraged and Calamos will have an incentive to be more aggressive and leverage the Fund. Consequently, the Fund and Calamos may have differing interests in determining whether to leverage the Fund’s assets. Any additional use of leverage by the Fund effected through new, additional or increased credit facilities or the issuance of preferred shares would require approval by the Board of Trustees of the Fund.

 

The following table illustrates the hypothetical effect on the return to a holder of the Fund’s common shares of the leverage obtained by us (and utilized on August 26, 2026). The purpose of this table is to assist you in understanding the effects of leverage. As the table shows, leverage generally increases the return to common shareholders when portfolio return is positive and greater than the cost of leverage and decreases the return when the portfolio return is negative or less than the cost of leverage. The figures appearing in the table are hypothetical and actual returns may be greater or less than those appearing in the table.

 

Assumed Portfolio Return (Net of Expenses)			(10.00	)%			(5.00	)%			0.00	%			5.00	%			10.00	%
Corresponding Common Share Return(l)			(16.79	)%			(9.38	)%			(1.98	)%			5.43	%			12.84	%

 

(1) Includes interest expense on the borrowings under the SSB Agreement, accrued at interest rates in effect on August 26, 2026 of 4.19%, and dividend expense on the MRP Shares.

The following table provides information about our outstanding securities as of August 26, 2026:

 

Title of Class		Amount Authorized				Amount Held by the Fund for its Account				Amount Outstanding
Common Shares			Unlimited				0				80,436,056
MRPS-Series C			1,480,000				0				1,480,000
MRPS-Series E			1,460,000				0				1,460,000
MRPS-Series G			1,440,000				0				1,440,000
MRPS Series H			580,000				0				580,000