Mizuho Group reports 7% Spark I Acquisition (SPKL) holding in Schedule 13G

Rhea-AI Filing Summary

Mizuho Financial Group has disclosed a significant passive ownership position in Spark I Acquisition Corporation. As of December 31, 2025, Mizuho beneficially owned 436,195 common shares, representing 7.0% of the outstanding class.

Mizuho has sole voting and sole dispositive power over all 436,195 shares, with no shared voting or dispositive authority. The filing notes that Mizuho Financial Group, Mizuho Bank and Mizuho Americas may be indirect beneficial owners of shares directly held by Mizuho Securities USA LLC, their wholly owned subsidiary.

The stake is reported on a Schedule 13G, and Mizuho certifies the shares were acquired and are held in the ordinary course of business, without the purpose or effect of changing or influencing control of Spark I Acquisition Corporation.

Insights

Equity ownership and disclosure analyst

Mizuho reports a passive 7% stake in Spark I Acquisition via Schedule 13G.

The filing shows Mizuho Financial Group beneficially owns 436,195 common shares of Spark I Acquisition Corporation, equal to 7.0% of the class as of December 31, 2025. Mizuho holds sole voting and dispositive power over these shares.

The ownership is reported on Schedule 13G, which is used for passive holdings rather than control-seeking positions. The disclosure also explains that Mizuho Financial Group, Mizuho Bank and Mizuho Americas are indirect owners of shares held directly by Mizuho Securities USA LLC, their wholly owned subsidiary.

The certification states the position is held in the ordinary course of business and not with the purpose or effect of influencing control. Future updates to this ownership level or a switch to a Schedule 13D in later filings would signal a change in intent if they occur.

SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

SCHEDULE 13G

UNDER THE SECURITIES EXCHANGE ACT OF 1934

Spark I Acquisition Corporation

(Name of Issuer)

Common Shares

(Title of Class of Securities)

G8316B100

(CUSIP Number)

12/31/2025

(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)

SCHEDULE 13G

CUSIP No. G8316B100

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 436,195.00
6	Shared Voting Power 0.00
7	Sole Dispositive Power 436,195.00
8	Shared Dispositive Power 0.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

436,195.00

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)

7.0 %

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: Spark I Acquisition Corporation
(b)	Address of issuer's principal executive offices: 3790 El Camino Real Unit #570, Palo Alto, CA 94306
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 No.: G8316B100
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: 436,195
(b)	Percent of class: 7.0 %
(c)	Number of shares as to which the person has:
	(i) Sole power to vote or to direct the vote: 436,195
	(ii) Shared power to vote or to direct the vote: 0
	(iii) Sole power to dispose or to direct the disposition of: 436,195
	(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:	02/12/2026

FAQ

What stake does Mizuho Financial Group hold in Spark I Acquisition Corporation (SPKL)?

Mizuho Financial Group beneficially owns 436,195 common shares of Spark I Acquisition Corporation, representing a 7.0% interest in the class as of December 31, 2025. This gives Mizuho a notable, but still minority, passive ownership position.

Is Mizuho’s ownership in Spark I Acquisition (SPKL) a passive investment?

Yes. The position is disclosed on Schedule 13G, which is used for passive holdings. Mizuho certifies the shares were acquired and are held in the ordinary course of business and not for the purpose or effect of changing or influencing control of Spark I Acquisition.

How many Spark I Acquisition (SPKL) shares can Mizuho vote or dispose of?

Mizuho has sole voting and sole dispositive power over all 436,195 Spark I Acquisition common shares it beneficially owns. The filing reports no shared voting power and no shared dispositive power, indicating full unilateral authority over these specific shares.

Which Mizuho entities are linked to the Spark I Acquisition (SPKL) shares?

The filing states Mizuho Financial Group, Inc., Mizuho Bank, Ltd. and Mizuho Americas LLC may be deemed indirect beneficial owners of the Spark I Acquisition shares directly held by Mizuho Securities USA LLC, which is a wholly owned subsidiary of these Mizuho entities.

Why did Mizuho file a Schedule 13G for Spark I Acquisition (SPKL)?

Mizuho filed Schedule 13G because its beneficial ownership in Spark I Acquisition exceeded 5% and is being reported as a passive position. The certification confirms the securities were acquired and are held in the ordinary course of business, not to influence the issuer’s control.

What percentage of Spark I Acquisition (SPKL) does Mizuho’s 436,195 shares represent?

Mizuho’s 436,195 Spark I Acquisition common shares represent 7.0% of the outstanding class. This level of ownership triggers beneficial ownership reporting requirements and is large enough to be relevant, while still leaving control with other shareholders and stakeholders.