SCHEDULE 13G 0000919185 XXXXXXXX LIVE Ordinary Shares, par value $0.0001 per share 09/30/2025 0002070900 Quantumsphere Acquisition Corp G7387B106 1185 6TH AVE., SUITE 304 NEW YORK NY 10036 Rule 13d-1(b) HIGHBRIDGE CAPITAL MANAGEMENT LLC DE 600000.00 0.00 600000.00 0.00 600000.00 N 5.3 IA OO Quantumsphere Acquisition Corp 1185 Avenue of the Americas, Suite 304, New York, NY, 10036. This statement is filed by Highbridge Capital Management, LLC ("Highbridge" or the "Reporting Person"), a Delaware limited liability company and the investment adviser to certain funds and accounts (the "Highbridge Funds"), with respect to the ordinary shares, par value $0.0001 per share ("Ordinary Shares"), of Quantumsphere Acquisition Corporation, a Cayman Islands exempted company (the "Issuer"), directly held by the Highbridge Funds. The filing of this statement should not be construed as an admission that any of the foregoing persons or the Reporting Person is, for the purposes of Section 13 of the Securities Exchange Act of 1934, the beneficial owner of the securities reported herein. The address of the business office of the Reporting Person is 277 Park Avenue, 23rd Floor, New York, New York 10172. Highbridge is a Delaware limited liability company. N IA The information required by Item 4(a) is set forth in Row 9 of the cover page for the Reporting Person and is incorporated herein by reference. The percentage set forth in this Schedule 13G is calculated based upon an aggregate of 11,406,650 Ordinary Shares outstanding as of September 18, 2025, as reported in the Issuer's Quarterly Report on Form 10-Q for the quarterly period ended June 30, 2025, filed with the Securities and Exchange Commission on September 19, 2025. 5.3% The information required by 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 Item 4(c)(ii) is set forth in Row 6 of the cover page for the Reporting Person and is incorporated herein by reference. The information required by Item 4(c)(iii) is set forth in Row 7 of the cover page for the Reporting Person and is incorporated herein by reference. The information required by Item 4(c)(iv) is set forth in Row 8 of the cover page for the Reporting Person and is incorporated herein by reference. Y N See Item 2(a). The Highbridge Funds have the right to receive or the power to direct the receipt of dividends from, or the proceeds from the sale of, the Ordinary Shares reported herein. 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. HIGHBRIDGE CAPITAL MANAGEMENT LLC /s/ Kirk Rule 11/14/2025