DMYY · dMY Squared Technology Group, Inc.

The shares of Class B common stock, par value $0.0001 per share ("Class B Common Stock"), are convertible into shares of the issuer's Class A common stock, par value $0.0001 per share ("Class A Common Stock"), at the holder's election at any time and automatically at the time of the closing of the issuer's initial business combination, on a one-for-one basis, subject to adjustment pursuant to certain antidilution rights and have no expiration date.

In connection with and immediately prior to the closing of the business combination ("Business Combination") between dMY Squared Technology Group, Inc., Horizon Quantum Computing Pte. Ltd., and Horizon Quantum Holdings Ltd., all of the outstanding shares of Class B Common Stock were converted on a one-for-one basis into shares of Class A Common Stock in accordance with the issuer's Amended and Restated Articles of Organization.

dMY Squared Sponsor, LLC (the "Sponsor") Sponsor is the record holder of the securities reported herein. Harry L. You is the managing member of the Sponsor and has voting and investment discretion with respect to the securities held of record by the Sponsor. Each of the Sponsor and Mr. You is a "Reporting Person" and may be deemed to beneficially own the securities reported herein; however, each Reporting Person disclaims beneficial ownership of the securities reported herein, except to the extent of such Reporting Person's pecuniary interest therein. Solely for purposes of Section 16 of the Exchange Act, each Reporting Person may be deemed a "director by deputization".

In connection with and immediately prior to the closing of the business combination ("Business Combination") between dMY Squared Technology Group, Inc., Horizon Quantum Computing Pte. Ltd., and Horizon Quantum Holdings Ltd., all of the outstanding shares of Class B Common Stock were converted on a one-for-one basis into shares of Class A Common Stock in accordance with the issuer's Amended and Restated Articles of Organization.

dMY Squared Sponsor, LLC (the "Sponsor") Sponsor is the record holder of the securities reported herein. Harry L. You is the managing member of the Sponsor and has voting and investment discretion with respect to the securities held of record by the Sponsor. Each of the Sponsor and Mr. You is a "Reporting Person" and may be deemed to beneficially own the securities reported herein; however, each Reporting Person disclaims beneficial ownership of the securities reported herein, except to the extent of such Reporting Person's pecuniary interest therein. Solely for purposes of Section 16 of the Exchange Act, each Reporting Person may be deemed a "director by deputization".

The shares of Class B common stock, par value $0.0001 per share, are convertible for shares of the issuer's Class A common stock, par value $0.0001 per share, at the holder's election at any time and automatically at the time of the closing of the issuer's initial business combination, on a one-for-one basis, subject to adjustment pursuant to certain antidilution rights and have no expiration date.

dMY Squared Sponsor, LLC (the "Sponsor") distributed these shares to one of its members, pro rata, for no consideration.

The Sponsor is the record holder of the securities reported herein. Harry L. You is the managing member of the Sponsor and has voting and investment discretion with respect to the securities held of record by the Sponsor. Each of the Sponsor and Mr. You is a "Reporting Person" and may be deemed to beneficially own the securities reported herein; however, each Reporting Person disclaims beneficial ownership of the securities reported herein, except to the extent of such Reporting Person's pecuniary interest therein. Solely for purposes of Section 16 of the Exchange Act, each Reporting Person may be deemed a "director by deputization".

The securities reported herein are beneficially owned by Sandia Investment Management L.P. ("Sandia") in its capacity as investment manager to a private investment vehicle and separately managed accounts. Mr. Sichler serves as Managing Member of the general partner of Sandia, and in such capacity may be deemed to indirectly beneficially own the securities reported herein. Each of the Reporting Persons disclaims beneficial ownership of the shares reported herein except to the extent of its or his pecuniary interest therein, and the filing of this Form 4 shall not be construed as an admission that any of the Reporting Persons is the beneficial owner of any such shares for purposes of Section 16(a) of the Securities Exchange Act of 1934 or for any other purpose.

The securities reported herein are beneficially owned by Sandia Investment Management L.P. ("Sandia") in its capacity as investment manager to a private investment vehicle and separately managed accounts. Mr. Sichler serves as Managing Member of the general partner of Sandia, and in such capacity may be deemed to indirectly beneficially own the securities reported herein. Each of the Reporting Persons disclaims beneficial ownership of the shares reported herein except to the extent of its or his pecuniary interest therein, and the filing of this Form 4 shall not be construed as an admission that any of the Reporting Persons is the beneficial owner of any such shares for purposes of Section 16(a) of the Securities Exchange Act of 1934 or for any other purpose.

The securities reported herein are beneficially owned by Sandia Investment Management L.P. ("Sandia") in its capacity as investment manager to a private investment vehicle and separately managed accounts. Mr. Sichler serves as Managing Member of the general partner of Sandia, and in such capacity may be deemed to indirectly beneficially own the securities reported herein. Each of the Reporting Persons disclaims beneficial ownership of the shares reported herein except to the extent of its or his pecuniary interest therein, and the filing of this Form 4 shall not be construed as an admission that any of the Reporting Persons is the beneficial owner of any such shares for purposes of Section 16(a) of the Securities Exchange Act of 1934 or for any other purpose.

The securities reported herein are beneficially owned by Sandia Investment Management L.P. ("Sandia") in its capacity as investment manager to a private investment vehicle and separately managed accounts. Mr. Sichler serves as Managing Member of the general partner of Sandia, and in such capacity may be deemed to indirectly beneficially own the securities reported herein. Each of the Reporting Persons disclaims beneficial ownership of the shares reported herein except to the extent of its or his pecuniary interest therein, and the filing of this Form 4 shall not be construed as an admission that any of the Reporting Persons is the beneficial owner of any such shares for purposes of Section 16(a) of the Securities Exchange Act of 1934 or for any other purpose.

The securities reported herein are beneficially owned by Sandia Investment Management L.P. ("Sandia") in its capacity as investment manager to a private investment vehicle and separately managed accounts. Mr. Sichler serves as Managing Member of the general partner of Sandia, and in such capacity may be deemed to indirectly beneficially own the securities reported herein. Each of the Reporting Persons disclaims beneficial ownership of the shares reported herein except to the extent of its or his pecuniary interest therein, and the filing of this Form 4 shall not be construed as an admission that any of the Reporting Persons is the beneficial owner of any such shares for purposes of Section 16(a) of the Securities Exchange Act of 1934 or for any other purpose.

The shares of Class B common stock are convertible for shares of the issuer's Class A common stock as described under the heading "Description of Securities" in the issuer's Registration Statement on Form S-1 (File No. 333-267381)(the "Registration Statement") and have no expiration date.

Adjusted to reflect the forfeiture of 431,250 shares of Class B common stock by dMY Squared Sponsor, LLC on September 29, 2022 as further describe in the issuer's Form 8-K filed on September 30, 2022 and the Exhibit 10.1 thereto. The shares of Class B common stock beneficially owned by the Reporting Person includes up to 225,000 shares of Class B common stock subject to forfeiture to the Issuer depending on the extent to which the underwriters' over-allotment option is exercised in connection with the Issuer's initial public offering of units, as described in the Registration Statement.

dMY Squared Sponsor, LLC is the record holder of the securities reported herein. Harry L. You is the manager of dMY Squared Sponsor, LLC and has voting and investment discretion with respect to the securities held of record by dMY Squared Sponsor, LLC.

The shares of Class B common stock are convertible for shares of the issuer's Class A common stock as described under the heading "Description of Securities" in the issuer's Registration Statement on Form S-1 (File No. 333-267381)(the "Registration Statement") and have no expiration date.

Adjusted to reflect the forfeiture of 431,250 shares of Class B common stock by dMY Squared Sponsor, LLC on September 29, 2022 as further described in the Issuer's Form 8-K filed on September 30, 2022 and the Exhibit 10.1 thereto. The shares of Class B common stock beneficially owned by the Reporting Person includes up to 225,000 shares of Class B common stock subject to forfeiture to the Issuer depending on the extent to which the underwriters' over-allotment option is exercised in connection with the Issuer's initial public offering of units, as described in the Registration Statement.

dMY Squared Sponsor, LLC is the record holder of the securities reported herein. Harry L. You is the manager of dMY Squared Sponsor, LLC and has voting and investment discretion with respect to the securities held of record by dMY Squared Sponsor, LLC.