SCHEDULE 13G 0001446580 XXXXXXXX LIVE Ordinary Shares, US$0.01 par value per share 12/31/2025 0001951222 SEALSQ Corp G79483106 Avenue Louis-Casai 58 Cointrin V8 1216 Rule 13d-1(b) Susquehanna Securities, LLC DE 9427841 9427841 9427841 9427841 9427841 5.3 BD OO SEALSQ Corp Avenue Louis-Casai 58, 1216 Cointrin, Switzerland This statement is filed by Susquehanna Securities, LLC, who is referred to herein as the "Reporting Person" with respect to the Ordinary Shares of SEALSQ Corp (the "Company"), US$0.01 par value per share (the "Shares"). 401 E. City Avenue Suite 220 Bala Cynwyd, PA 19004 Citizenship is set forth in Row 4 of the cover page for the Reporting Person and is incorporated herein by reference. N BD The information required by this Item 4(a) is set forth in Row 9 of the cover page for the Reporting Person and is incorporated herein by reference. The number of Shares reported as beneficially owned by the Reporting Person includes options to buy 8,731,200 Shares. The Company's Prospectus Supplement (to Prospectus dated October 20, 2025, Registration No. 333-290963), filed on October 20, 2025, indicates there were 177,400,997 Shares outstanding as of October 20, 2025. 5.3 The information required by this Item 4(c)(i) is set forth in Row 5 of the cover page for the Reporting Person and is incorporated herein by reference. The information required by this Item 4(c)(ii) is set forth in Row 5 of the cover page for the Reporting Person and is incorporated herein by reference. The information required by this Item 4(c)(iii) is set forth in Row 5 of the cover page for the Reporting Person and is incorporated herein by reference. The information required by this Item 4(c)(iv) is set forth in Row 5 of the cover page for the Reporting Person and is incorporated herein by reference. Y Y Y Y Y N By signing below I certify that, to the best of my knowledge and belief, the securities referred to above were acquired and are held in the ordinary course of business and were not acquired and are not held for the purpose of or with the effect of changing or influencing the control of the issuer of the securities and were not acquired and are not held in connection with or as a participant in any transaction having that purpose or effect, other than activities solely in connection with a nomination under ?? 240.14a-11. Susquehanna Securities, LLC /s/ Brian Sopinsky 02/12/2026