MCGAU · Yorkville Acquisition Corp. · Insider Trading

On May 4, 2026, the Issuer entered into an Amended and Restated Working Capital Note (the "Note") promising to pay Yorkville Acquisition Sponsor, LLC (the "Sponsor") $500,000. All amounts due under the Note may be converted into 50,000 units. Each unit consists of one Class A ordinary share and one-third of one warrant to purchase one Class A ordinary share, resulting in an aggregate of 50,000 Class A ordinary shares and warrants to purchase an additional 16,666 Class A ordinary shares of the Issuer at the discretion of the Sponsor upon the consummation of the business combinations. The warrants shall have the same terms and conditions as the warrants issued in the Issuer's initial public offering. The acquisition of the Note by the Sponsor, and through it, the beneficial acquisition of the Note by the Sponsor's members, is an exempt transaction under Rule 16b-3, promulgated by the U.S. Securities and Exchange Commission pursuant to the Securities Act of 1934, as amended.

The Issuer's Class A ordinary shares and warrants are described under the heading "Description of Securities" in the Issuer's Registration Statement on Form S-1 (File No. 333-286569).

The principal balance of the Note shall be payable by the Issuer on the earlier of the date on which the Issuer consummates its initial business combination or the date that the winding up of the Issuer is effective, and is convertible at the Sponsor's election upon the consummation of the initial business combination.

Yorkville Advisors Global, LP ("Yorkville LP") is the manager of the Sponsor and holds voting and investment discretion over the securities held by the Sponsor. YA II PN, Ltd. ("YA II PN") is a member of the Sponsor. Yorkville LP is the investment manager of YA II PN, and Yorkville Advisors Global II, LLC ("Yorkville LLC") is the General Partner of Yorkville LP. Mr. Angelo serves as President of Yorkville LLC and makes all investment decisions for YA II PN. As such, Mr. Angelo may be deemed to have beneficial ownership of the securities held by the Sponsor. Mr. Angelo disclaims any beneficial ownership of the reported securities, except to the extent of his pecuniary interest therein.

On May 4, 2026, the Issuer entered into an Amended and Restated Working Capital Note (the "Note") promising to pay Yorkville Acquisition Sponsor, LLC (the "Sponsor") $500,000. All amounts due under the Note may be converted into 50,000 units. Each unit consists of one Class A ordinary share and one-third of one warrant to purchase one Class A ordinary share, resulting in an aggregate of 50,000 Class A ordinary shares and warrants to purchase an additional 16,666 Class A ordinary shares of the Issuer at the discretion of the Sponsor upon the consummation of the business combinations. The warrants shall have the same terms and conditions as the warrants issued in the Issuer's initial public offering. The acquisition of the Note by the Sponsor, and through it, the beneficial acquisition of the Note by the Sponsor's members, is an exempt transaction under Rule 16b-3, promulgated by the U.S. Securities and Exchange Commission pursuant to the Securities Act of 1934, as amended.

The Issuer's Class A ordinary shares and warrants are described under the heading "Description of Securities" in the Issuer's Registration Statement on Form S-1 (File No. 333-286569).

The principal balance of the Note shall be payable by the Issuer on the earlier of the date on which the Issuer consummates its initial business combination or the date that the winding up of the Issuer is effective, and is convertible at the Sponsor's election upon the consummation of the initial business combination.

Yorkville Advisors Global, LP ("Yorkville LP") is the manager of the Sponsor and holds voting and investment discretion over the securities held by the Sponsor. YA II PN, Ltd. ("YA II PN") is a member of the Sponsor. Yorkville LP is the investment manager of YA II PN, and Yorkville Advisors Global II, LLC ("Yorkville LLC") is the General Partner of Yorkville LP. Mr. Angelo serves as President of Yorkville LLC and makes all investment decisions for YA II PN. As such, Mr. Angelo may be deemed to have beneficial ownership of the securities held by the Sponsor. Mr. Angelo disclaims any beneficial ownership of the reported securities, except to the extent of his pecuniary interest therein.

On February 11, 2026, the Issuer issued a convertible promissory note (the "Working Capital Note") in the principal amount of $250,000.00 to Yorkville Acquisition Sponsor, LLC (the "Sponsor"), in order to provide the Issuer with additional working capital.

Pursuant to the terms of the Working Capital Note, the principal balance shall not accrue interest; shall be payable by the Issuer on the earlier of the date on which the Issuer consummates its initial business combination or the date that the winding up of the Issuer is effective; and is convertible at the Sponsor's election upon the consummation of the Company's initial business combination. Should the Sponsor elect to convert all or a portion of the principal balance, the elected principal balance amount will convert, at a price of $10.00 per unit, into units identical to the private placement units issued in connection with the Issuer's initial public offering, rounded down to the nearest whole number.

Each unit will consist of (a) one Class A ordinary share and (b) one-third of one warrant to purchase one Class A ordinary share, at an exercise price of $11.50 per share, exercisable beginning 30 days after the completion of the Issuer's initial business combination, and expiring 5 years after the completion of the Issuer's initial business combination or earlier upon redemption or liquidation.

Yorkville Advisors Global, LP ("Yorkville LP") is the manager of the Sponsor and holds voting and investment discretion over the securities held by the Sponsor. YA II PN, Ltd. ("YA II PN") is a member of the Sponsor. Yorkville LP is the investment manager of YA II PN, and Yorkville Advisors Global II, LLC ("Yorkville LLC") is the General Partner of Yorkville LP. Mr. Angelo serves as President of Yorkville LLC and makes all investment decisions for YA II PN. As such, Mr. Angelo may be deemed to have beneficial ownership of the securities held by the Sponsor. Mr. Angelo disclaims any beneficial ownership of the reported securities, except to the extent of his pecuniary interest therein.

Simultaneously with the entry into a business combination agreement by the Issuer, the reporting person agreed to purchase those certain Class A Ordinary Shares from Clear Street LLC, upon closing of the business combination.

Simultaneously with the consummation of Yorkville Acquisition Corp.'s (the "Issuer") initial public offering, Yorkville Acquisition Sponsor LLC (the "Sponsor") purchased 351,825 Private Placement Units, each consisting of (i) one Class A ordinary share and (ii) one-third of one redeemable warrant, at a price of $10.00 per placement unit, or $3,518,250 in the aggregate.

Reflects the 351,825 Class A ordinary shares underlying the Private Placement Units.

YA II PN, Ltd. ("YA II PN") is the sole managing member of the Sponsor and holds voting and investment discretion over the securities held by the Sponsor. YA II PN is managed by Yorkville Advisors Global, LP ("Yorkville LP"), whose General Partner is Yorkville Advisors Global II, LLC ("Yorkville LLC"). All investment decisions for YA II PN are made by Mark Angelo, President and Managing Member of Yorkville LLC, and, as President and Managing Member of Yorkville LLC, Mr. Angelo may be deemed to have beneficial ownership of the securities held by the Sponsor. Mr. Angelo disclaims any beneficial ownership of the reported shares other than to the extent of any pecuniary interest he may have therein, directly or indirectly.

Simultaneously with the consummation of Yorkville Acquisition Corp.'s (the "Issuer") initial public offering, Yorkville Acquisition Sponsor LLC (the "Sponsor") purchased 351,825 Private Placement Units, each consisting of (i) one Class A ordinary share and (ii) one-third of one redeemable warrant, at a price of $10.00 per placement unit, or $3,518,250 in the aggregate.

Reflects the 351,825 Class A ordinary shares underlying the Private Placement Units.

YA II PN, Ltd. ("YA II PN") is the sole managing member of the Sponsor and holds voting and investment discretion over the securities held by the Sponsor. YA II PN is managed by Yorkville Advisors Global, LP ("Yorkville LP"), whose General Partner is Yorkville Advisors Global II, LLC ("Yorkville LLC"). All investment decisions for YA II PN are made by Mark Angelo, President and Managing Member of Yorkville LLC, and, as President and Managing Member of Yorkville LLC, Mr. Angelo may be deemed to have beneficial ownership of the securities held by the Sponsor. Mr. Angelo disclaims any beneficial ownership of the reported shares other than to the extent of any pecuniary interest he may have therein, directly or indirectly.