0001840904 2025-12-05 2025-12-05 0001840904 1 2025-12-05 2025-12-05 shares iso4217:USD shares iso4217:USD pure Atai Beckley N.V. false Equity true 123134069 3.79 466678121.51 0.0001381 64448.25 466678121.51 64448.25 0 0 64448.25 <table style="font-size: 12pt; border-spacing: 0px; border-collapse: collapse; width: 100%;"> <tr style="height: 0px; font-size: 0px;"><td style="width: 2%;"> </td><td style="width: 98%;"> </td></tr><tr style="vertical-align: top;"> <td style="padding: 0px 0pt; font-size: 10pt;"> <div style="margin-bottom: 4pt;"> (1) </div> </td> <td style="padding-top: 0px; padding-right: 5.4pt; padding-bottom: 0px; text-align: left; font-size: 10pt;"> <div style="margin-bottom: 4pt;"> <span>With respect to this secondary offering, this prospectus supplement registers 123,134,069 common shares to be sold by the selling securityholders named therein. Pursuant to Rule 416 under the Securities Act of 1933, as amended, or the Securities Act, this prospectus supplement also relates to an indeterminate number of additional common shares that may be issued with respect to such common shares by way of stock splits, stock dividends, reclassifications or similar transactions.</span> </div> </td> </tr> </table><table style="font-size: 12pt; border-spacing: 0px; border-collapse: collapse; width: 100%;"> <tr style="height: 0px; font-size: 0px;"><td style="width: 2%;"> </td><td style="width: 98%;"> </td></tr><tr style="vertical-align: top;"> <td style="padding: 0px 0pt; font-size: 10pt;"> <div style="margin-bottom: 4pt;"> (2) </div> </td> <td style="padding-top: 0px; padding-right: 5.4pt; padding-bottom: 0px; text-align: left; font-size: 10pt;"> <div style="margin-bottom: 4pt;"> <span>Estimated solely purposes of calculating the registration fee pursuant to Rule 457(c) under the Securities Act, on the basis of the average of the high and low prices for a common share as reported on the Nasdaq Global Market on December 1, 2025, which date is a date within five business days of the filing date of this prospectus supplement.</span> </div> </td> </tr> </table> 424B7 Secondary Offering: Common shares, par value Euro0.10 per share N/A 0001840904 EX-FILING FEES S-3 N/A 333-290592