SCHEDULE 13D/A 0001193125-21-171001 0001840904 XXXXXXXX LIVE 5 Ordinary Shares 10/27/2025 false 0001816590 20451W101 COMPASS Pathways plc

33 Broadwick Street London X0 W1F 0DQ

Ryan Barrett 49 (0) 89 2153 9035 Prof. J.H. Bavincklaan 7 Amstelveen P7 1183AT 0001840904 ATAI Life Sciences N.V. WC P7 0 5785774 0 5785774 5785774 N 6 CO Y ATAI Life Sciences GmbH (formerly ATAI Life Sciences AG) WC 2M 0 0 0 0 0 N 0 CO Ordinary Shares COMPASS Pathways plc 33 Broadwick Street London X0 W1F 0DQ This Amendment No. 5 to Schedule 13D amends and supplements the Schedule 13D originally filed with the United States Securities and Exchange Commission (the "SEC") on May 24, 2021 (as amended, the "Schedule 13D") relates to the ordinary shares, nominal value GBP 0.008 per ordinary share (the "Ordinary Shares"), of COMPASS Pathways plc, a public limited company under the laws of England and Wales (the "Issuer"). Capitalized terms used herein without definition shall have the meaning set forth in the Schedule 13D. CUSIP number 20451W101 has been assigned to the American Depositary Shares ("ADSs") of the Issuer, which are quoted on The Nasdaq Stock Market under the symbol "CMPS." Each ADS represents one Ordinary Share of the Issuer. No CUSIP number has been assigned to the Ordinary Shares of the Issuer. In connection with a corporate reorganization, ATAI Life Sciences AG was converted into a German GmbH in April 2025. As a result, the Ordinary Shares of the Issuer reported herein are held directly by ATAI Life Sciences N.V Item 5 of the Schedule 13D is amended and restated in its entirety by inserting the following information: The information contained on the cover pages is incorporated by reference to this Item 5. As of the date of this Schedule 13D, ATAI N.V. may be deemed to beneficially own 5,785,774 Ordinary Shares, representing approximately 6.0% of the 95,941,264 Ordinary Shares outstanding as of July 28, 2025, as disclosed in the Issuer's Quarterly Report on Form 10-Q filed by the Issuer on July 31, 2025. The information contained on the cover pages is incorporated by reference to this Item 5. ATAI N.V. directly holds the securities reported herein. During the past 60 days, ATAI N.V. effected the following open market sales of ADSs representing Ordinary Shares: 10/22/2025: 20,000 shares for $6.3194 per share. 10/23/2025: 20,000 shares for $6.2949 per share. 10/24/2025: 60,000 shares for $6.3714 per share. 10/27/2025: 60,000 shares for $6.5801 per share. 10/28/2025: 60,000 shares for $6.4946 per share. None. In connection with a corporate reorganization that occurred in April 2025, ATAI AG ceased to be the beneficial owner of any Ordinary Shares of the Issuer. ATAI Life Sciences N.V. /s/ Anne Johnson 10/29/2025 ATAI Life Sciences GmbH (formerly ATAI Life Sciences AG) /s/ Anne Johnson 10/29/2025