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2026-03-31
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2026-03-31
<p style="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: center"><b>CALAMOS ETF TRUST</b></p>
<p style="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: center">(the “Trust”)</p><p style="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0"> </p>
<p style="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: center"><b>Calamos S&P 500<sup>® </sup>Structured
Alt Protection ETF<sup>®</sup> – April</b></p>
<p style="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: center">(the “Fund”)</p><p style="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0"> </p>
<p style="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: center">Supplement dated March 31, 2026</p>
<p style="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: center">to the Fund’s Prospectus dated November 28,
2025, as amended</p><p style="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0"> </p>
<p style="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: center"><i>This supplement updates certain information
contained in the Fund’s prospectus and should be attached to the prospectus and retained for future reference.</i></p><p style="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0"> </p>
<p style="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: center"><i>Capitalized terms not defined herein have the
same meaning as in the Fund’s prospectus.</i></p><p style="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0"> </p>
<p style="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0">As described in the Fund’s prospectus, an investment in shares
of the Fund is subject to an upside return cap (the “Cap”) that represents the maximum percentage return an investor can achieve
from an investment in the Fund for the Outcome Period of approximately one year. The Fund’s current Outcome Period will end on March 31,
2026. The next Outcome Period will begin on April 1, 2026 and end on March 31, 2027 (the “Upcoming Outcome Period”).
The Fund’s Cap for the Outcome Period beginning on April 1, 2026 is set forth below.</p><p style="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0"> </p>
<p style="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: center">6.70%</p>
<p style="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: center">(6.01% after taking into account the Fund’s
management fees)</p><p style="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0"> </p>
<p style="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0">The Fund’s return will be further reduced by brokerage commissions,
trading fees, taxes and non-routine or extraordinary expenses not included in the Fund’s management fee, as described in the prospectus.</p><p style="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0"> </p>
<p style="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0">Effective April 1, 2026, the Fund’s Prospectus is amended
to revise all references to the Outcome Period and Cap to reflect the information above.</p><p style="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0"> </p>
<p style="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0">On April 1, 2026, the Fund’s summary prospectus will be
amended to update all references to the Cap and Outcome Period to reflect the Cap and new Outcome Period, as described above.</p>
Calamos S&P 500® Structured
Alt Protection ETF® – April
2025-11-28
497
N-1A
0001579881
false
2026-03-31
Calamos ETF Trust