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&lt;p style="font: 14pt Times New Roman, Times, Serif; margin: 0 0 0 0.15pt; text-align: center"&gt;Janus Henderson Global
Artificial Intelligence ETF&lt;/p&gt;

&lt;p style="font: 11pt Times New Roman, Times, Serif; margin: 0; text-align: center"&gt;Supplement dated April 30, 2026&lt;/p&gt;

&lt;p style="font: 11pt Times New Roman, Times, Serif; margin: 0 0 0 0.05pt; text-align: center"&gt;to Currently Effective
Prospectuses &lt;span style="display: none"&gt;&lt;span id="xdx_906_eoef--ProspectusDate_c20260430__20260430_zqEMFSE5xqul"&gt;02/27/2026&lt;/span&gt;&lt;/span&gt;&lt;/p&gt;

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&lt;p style="font: 11pt Times New Roman, Times, Serif; margin: 0 0 0 5pt"&gt;Effective immediately, the prospectuses for the
&lt;b&gt;Janus Henderson Global Artificial Intelligence ETF &lt;/b&gt;(the &#x201c;Fund&#x201d;) is amended as follows:&lt;/p&gt;

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&lt;td style="width: 12pt"&gt;&lt;span&gt;1.&lt;/span&gt;&lt;/td&gt;&lt;td&gt;&lt;span style="font-family: Times New Roman, Times, Serif"&gt;Under &#x201c;&lt;b&gt;Principal Investment Strategy&lt;/b&gt;&#x201d; in the &lt;b&gt;Fund Summary&lt;/b&gt;
section of the Fund&#x2019;s prospectuses, the following replaces the corresponding paragraph in its entirety&lt;span&gt;:&lt;/span&gt;&lt;/span&gt;&lt;/td&gt;&lt;/tr&gt;&lt;/table&gt;

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&lt;p style="font: 11pt Times New Roman, Times, Serif; margin: 0 0 0 0.5in"&gt;The Fund typically invests in approximately 40-60 equity
securities of companies of any size and any sector. Under normal circumstances, the Fund typically invests at least 40% of its net assets
in securities of issuers or companies that are economically tied to countries outside the United States. The Fund will not invest more
than 25% of its net assets in emerging markets and will only invest in foreign securities listed on U.S. exchanges or in the form of depositary
receipts. An issuer is deemed to be economically tied to a country or countries outside of the United States if one or more of the following
tests are met: (i) the issuer is organized in, or its primary business office or primary trading market of its equity is located in, a
country outside of the United States (ii) a majority of the issuers&#x2019; revenues are derived from outside of the United States, or
(iii) a majority of the issuer&#x2019;s assets are located outside of the United States.&lt;/p&gt;

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&lt;p style="font: 11pt Times New Roman, Times, Serif; margin: 0; text-align: center"&gt;Please retain this Supplement with your records.&lt;/p&gt;

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    <oef:ProspectusDate contextRef="AsOf2026-04-30" id="Fact000015">2026-02-27</oef:ProspectusDate>
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