SCHEDULE 13D/A 0001848787 XXXXXXXX LIVE 2 Common Stock, $0.0001 par value 02/12/2026 false 0002007825 45676K103 Infleqtion, Inc.

1315 West Century Drive Suite 150 Louisville CO 80027

Jay Taragin (212) 380-7500 640 Fifth Avenue, 14th Floor New York NY 10019 0001848787 N Churchill Sponsor X LLC WC N DE 10725000 0 10725000 0 10725000 N 4.9 OO (1) Includes (i) 10,650,000 shares of the Issuer's common stock, $0.0001 par value ("Common Stock") and (ii) 75,000 shares of Common Stock underlying private placement warrants of the Issuer ("Warrants"). Michael Klein, the former Chief Executive Officer and Director of the Issuer, is the controlling stockholder of M. Klein Associates, Inc., which is the managing member of Churchill Sponsor X LLC (the "Sponsor"), and accordingly Mr. Klein may be deemed to have beneficial ownership of securities reported herein. Mr. Klein disclaims any ownership of securities reported herein other than to the extent of any pecuniary interest he may have therein, directly or indirectly. 0001751504 N M. Klein Associates, Inc. OO N NY 0 10725000 0 10725000 10725000 N 4.9 OO (1) Includes (i) 10,650,000.00 shares of Common Stock and (ii) 75,000 shares of Common Stock underlying the Warrants. Michael Klein, the former Chief Executive Officer and Director of the Issuer, is the controlling shareholder of M. Klein Associates, Inc., which is the managing member of the Sponsor, and accordingly Mr. Klein may be deemed to have beneficial ownership of securities reported herein. Mr. Klein disclaims any ownership of securities reported herein other than to the extent of any pecuniary interest he may have therein, directly or indirectly. 0001327392 N Michael Klein OO N X1 0 10725000 0 10725000 10725000 N 4.9 IN (1) Includes (i) 10,650,000.00 shares of Common Stock and (ii) 75,000 shares of Common Stock underlying the Warrants. Michael Klein, the former Chief Executive Officer and Director of the Issuer, is the controlling shareholder of M. Klein Associates, Inc., which is the managing member of the Sponsor, and accordingly Mr. Klein may be deemed to have beneficial ownership of securities reported herein. Mr. Klein disclaims any ownership of securities reported herein other than to the extent of any pecuniary interest he may have therein, directly or indirectly. Common Stock, $0.0001 par value Infleqtion, Inc. 1315 West Century Drive Suite 150 Louisville CO 80027 The following constitutes Amendment No. 2 ("Amendment No. 2") to the Schedule 13D filed with the Securities and Exchange Commission on May 21, 2025 (the "Initial 13D"), as previously amended by Amendment No. 1 ("Amendment No. 1") on September 11, 2025 (collectively, the "Schedule 13D") by Churchill Sponsor X LLC, a Delaware limited liability company (the "Sponsor"), M. Klein Associates, Inc. ("M. Klein Associates") and Michael Klein (collectively, the "Reporting Persons"). This Amendment No. 2 represents the final amendment to the Schedule 13D and constitutes an "exit filing" for the Reporting Person. Capitalized terms used herein and not otherwise defined in this Amendment No. 2 have the meanings set forth in Amendment No. 1. The following amends and restates the information set forth in Item 4 of Amendment No. 1 by adding the following at the end thereof: Pursuant to the Merger Agreement, the Domestication and the Mergers were completed on February 12 and February 13, 2026, respectively. Prior to the consummation of the Domestication and the Mergers, the Reporting Person held (i) 10,350,000 Class B ordinary shares of Churchill Capital Corp X ("Churchill") and (ii) 300,000 private placement units of Churchill (each unit consisting of one Class A ordinary share, par value $0.0001 per share, of Churchill and one quarter of one warrant, with the warrant only becoming exercisable 30 days after the completion of the Mergers). Upon the Domestication and pursuant to the Merger Agreement, the securities of Churchill held by the Reporting Person automatically converted into (i) 10,650,000 shares of common stock, par value $0.0001 per share, of the Issuer ("Common Stock") and (ii) 75,000 private placement warrants of the Issuer, which will become exercisable 30 days after the completion of the Mergers. Effective upon the completion of the Mergers, the A&R Registration Rights Agreement and Advisory Agreement became effective in accordance with their terms, as previously reported. See rows (11) and (13) of the cover page to this Schedule 13D for the aggregate number of Class A Ordinary Shares and percentage of Common Stock beneficially owned by each of the Reporting Persons. See rows (7) through (10) of the cover page to this Schedule 13D for the Common Stock as to which each of the Reporting Persons has the sole or shared power to vote or direct the vote and sole or shared power to dispose or to direct the disposition. Mr. Klein is the controlling stockholder of M. Klein Associates, which is the managing member of the Sponsor and accordingly, Mr. Klein may be deemed to have beneficial ownership of securities reported herein. Mr. Klein disclaims any ownership of securities reported herein other than to the extent of any pecuniary interest he may have therein, directly or indirectly. Except as set forth in Item 4, none of the Reporting Persons has effected any transactions of Ordinary Shares or Common Stock during the 60 days preceding the date of this report. Not applicable. Not applicable. Item 4 of this Amendment No. 2 is incorporated herein by reference. Churchill Sponsor X LLC /s/ Jay Taragin 02/17/2026 /s/ Jay Taragin 02/17/2026 M. Klein Associates, Inc. /s/ Jay Taragin 02/17/2026 Michael Klein /s/ Michael Klein 02/17/2026