Mizuho Files Schedule 13G Showing 7.2% Stake in Yorkville

Yorkville Acquisition Corp. ownership disclosure: Mizuho Financial Group, Inc. reports beneficial ownership of 1,292,253 shares of Common Shares, representing 7.2% of the class as reported with an 03/31/2026 time anchor.

Rhea-AI Filing Summary

Yorkville Acquisition Corp. ownership disclosure: Mizuho Financial Group, Inc. reports beneficial ownership of 1,292,253 shares of Common Shares, representing 7.2% of the class as reported with an 03/31/2026 time anchor. The filing states Mizuho holds sole voting and sole dispositive power over these shares through its subsidiary structure and includes a parent/subsidiary attribution note.

The Schedule 13G is signed by a Mizuho representative and characterizes the parent holding company relationship; it notes that Mizuho Securities USA LLC directly holds the securities.

Insights

Corporate Governance Expert

Passive 13G shows a notable 7.2% stake by Mizuho.

The filing reports that Mizuho Financial Group, Inc. beneficially owns 1,292,253 shares with sole voting and dispositive power as of 03/31/2026. It identifies the subsidiary that directly holds the securities for parent attribution.

Ownership at this level can affect proxy dynamics; subsequent filings would show whether the position remains passive or converts to active status.

Equity Ownership Analyst

Disclosure clarifies control via subsidiary and reports voting/disposition powers.

The schedule explicitly attributes holdings to Mizuho and notes indirect ownership through Mizuho Securities USA LLC and related entities. The filing lists sole voting and sole dispositive power over 1,292,253 shares.

Cash‑flow treatment and any intended disposition are not stated; future amendments would indicate any change in intent.

Key Figures

Beneficial ownership: 1,292,253 shares Percent of class: 7.2% Voting/Dispositive Power: 1,292,253 shares (sole)

3 metrics

Beneficial ownership 1,292,253 shares as reported in Schedule 13G with date <date>03/31/2026</date>

Percent of class 7.2% percent of Common Shares reported in Item 4(b)

Voting/Dispositive Power 1,292,253 shares (sole) sole power to vote and sole power to dispose as stated in Item 4(c)(i) and 4(c)(iii)

Key Terms

Schedule 13G, Beneficially owned, Sole Dispositive Power

3 terms

Schedule 13G regulatory

"Item 2. | (a) | Name of person filing: Mizuho Financial Group, Inc."

A Schedule 13G is a formal document that investors file with the government when they acquire a large ownership stake in a company, usually for investment purposes rather than control. It helps keep the public informed about who owns significant parts of a company's shares, which can influence how the company is managed and how investors make decisions. Filing this schedule is important for transparency and understanding the ownership landscape of publicly traded companies.

Beneficially owned regulatory

"Item 4. | Ownership (a) | Amount beneficially owned: 1,292,253"

Beneficially owned describes securities or assets where a person has the economic rights and control—such as the right to receive dividends and to direct voting—even if legal title is held in another name. Think of it like having the keys and using a car that’s registered to someone else: you get the benefits and make decisions. Investors care because beneficial ownership reveals who truly controls value and voting power, affecting corporate decisions and takeover dynamics.

Sole Dispositive Power regulatory

"Item 4. | (iii) Sole power to dispose or to direct the disposition of: 1,292,253"

Sole dispositive power is the exclusive legal authority to decide what happens to a security — for example, whether to sell, transfer, or retain shares — without needing anyone else’s permission. Investors care because it signals who truly controls the economic outcome of an investment: like holding the only key to a safe, the holder can realize gains or losses and may trigger regulatory reporting, insider rules, or influence over corporate ownership.

FAQ

AI-generated questions and answers. How Rhea-AI works. Not financial advice.

What stake does Mizuho hold in Yorkville Acquisition Corp. (MCGA)?

Mizuho Financial Group, Inc. reports beneficial ownership of 1,292,253 shares, representing 7.2% of Common Shares as of 03/31/2026. The filing attributes sole voting and dispositive power to Mizuho over these shares.

How does Mizuho hold the MCGA shares reported in the Schedule 13G?

The Schedule 13G states the shares are directly held by Mizuho Securities USA LLC, with indirect beneficial ownership attributed to Mizuho Financial Group and affiliated entities. A parent/subsidiary attribution note appears in the filing.

Does the Schedule 13G indicate Mizuho intends to actively control MCGA?

The filing is a Schedule 13G disclosure and does not state an intent to take control. It reports beneficial ownership and voting/dispositive power; it does not convert the position into an active or controlling statement.

Who signed the Schedule 13G on behalf of Mizuho?

The Schedule 13G is signed by Takahiro Katsura, identified as Managing Director, Global Corporate Function Coordination Department, with the signature dated 05/14/2026 on the filing.

Does the filing disclose how Mizuho will dispose of or vote these shares?

The filing states Mizuho has sole voting and sole dispositive power over the reported 1,292,253 shares, but it does not disclose any plan or schedule for disposition or specific voting intentions.

AI-generated analysis. How Rhea-AI works. Not financial advice.

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Accepted by SEC EDGAR 05/14/2026 - 06:21 AM Learn about SEC filing dates

SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

SCHEDULE 13G

UNDER THE SECURITIES EXCHANGE ACT OF 1934

Yorkville Acquisition Corp.

(Name of Issuer)

Common Shares

(Title of Class of Securities)

G98659116

(CUSIP Number)

03/31/2026

(Date of Event Which Requires Filing of this Statement)

Check the appropriate box to designate the rule pursuant to which this Schedule is filed:

Rule 13d-1(b)

Rule 13d-1(c)

Rule 13d-1(d)

schemaVersion:

SCHEDULE 13G

CUSIP Number(s): G98659116

1

Names of Reporting Persons

Mizuho Financial Group, Inc.

2

Check the appropriate box if a member of a Group (see instructions)

(a)
(b)

3

Sec Use Only

4

Citizenship or Place of Organization

JAPAN

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 1,292,253.00
6	Shared Voting Power 0.00
7	Sole Dispositive Power 1,292,253.00
8	Shared Dispositive Power 0.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

1,292,253.00

10

Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)

11

Percent of class represented by amount in row (9)

7.2 %

12

Type of Reporting Person (See Instructions)

FI

Comment for Type of Reporting Person: Mizuho Financial Group, Inc., Mizuho Bank, Ltd. and Mizuho Americas LLC may be deemed to be indirect beneficial owners of said equity securities directly held by Mizuho Securities USA LLC which is their wholly-owned subsidiary.

SCHEDULE 13G

Item 1.
(a)	Name of issuer: Yorkville Acquisition Corp.
(b)	Address of issuer's principal executive offices: 1012 Springfield Avenue, Mountainside, NJ, 07092
Item 2.
(a)	Name of person filing: Mizuho Financial Group, Inc.
(b)	Address or principal business office or, if none, residence: 1-5-5, Otemachi, Chiyoda-ku, Tokyo, 100-8176, Japan
(c)	Citizenship: Japan
(d)	Title of class of securities: Common Shares
(e)	CUSIP Number(s): G98659116
Item 3.	If this statement is filed pursuant to §§ 240.13d-1(b) or 240.13d-2(b) or (c), check whether the person filing is a:
(a)	Broker or dealer registered under section 15 of the Act (15 U.S.C. 78o);
(b)	Bank as defined in section 3(a)(6) of the Act (15 U.S.C. 78c);
(c)	Insurance company as defined in section 3(a)(19) of the Act (15 U.S.C. 78c);
(d)	Investment company registered under section 8 of the Investment Company Act of 1940 (15 U.S.C. 80a-8);
(e)	An investment adviser in accordance with § 240.13d-1(b)(1)(ii)(E);
(f)	An employee benefit plan or endowment fund in accordance with § 240.13d-1(b)(1)(ii)(F);
(g)	A parent holding company or control person in accordance with § 240.13d-1(b)(1)(ii)(G);
(h)	A savings associations as defined in Section 3(b) of the Federal Deposit Insurance Act (12 U.S.C. 1813);
(i)	A church plan that is excluded from the definition of an investment company under section 3(c)(14) of the Investment Company Act of 1940 (15 U.S.C. 80a-3);
(j)	A non-U.S. institution in accordance with § 240.13d-1(b)(1)(ii)(J). If filing as a non-U.S. institution in accordance with § 240.13d-1(b)(1)(ii)(J), please specify the type of institution:
(k)	Group, in accordance with Rule 240.13d-1(b)(1)(ii)(K).
	Parent Holding Company
Item 4.	Ownership
(a)	Amount beneficially owned: 1,292,253
(b)	Percent of class: 7.2 %
(c)	Number of shares as to which the person has:
	(i) Sole power to vote or to direct the vote: 1,292,253
	(ii) Shared power to vote or to direct the vote: 0
	(iii) Sole power to dispose or to direct the disposition of: 1,292,253
	(iv) Shared power to dispose or to direct the disposition of: 0
Item 5.	Ownership of 5 Percent or Less of a Class.
	Not Applicable
Item 6.	Ownership of more than 5 Percent on Behalf of Another Person.
	Not Applicable
Item 7.	Identification and Classification of the Subsidiary Which Acquired the Security Being Reported on by the Parent Holding Company or Control Person.
	If a parent holding company has filed this schedule, pursuant to Rule 13d-1(b)(ii)(G), so indicate under Item 3(g) and attach an exhibit stating the identity and the Item 3 classification of the relevant subsidiary. If a parent holding company has filed this schedule pursuant to Rule 13d-1(c) or Rule 13d-1(d), attach an exhibit stating the identification of the relevant subsidiary. See Exhibit A
Item 8.	Identification and Classification of Members of the Group.
	Not Applicable
Item 9.	Notice of Dissolution of Group.
	Not Applicable

Item 10.

Certifications:

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. By signing below I certify that, to the best of my knowledge and belief, the foreign regulatory scheme applicable to Parent Holding Company is substantially comparable to the regulatory scheme applicable to the functionally equivalent U.S. institution(s). I also undertake to furnish to the Commission staff, upon request, information that would otherwise be disclosed in a Schedule 13D.

SIGNATURE

After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.

Mizuho Financial Group, Inc.

Signature:	/s/ Takahiro Katsura
Name/Title:	Takahiro Katsura, Managing Director, Global Corporate Function Coordination Department
Date:	05/14/2026