[SCHEDULE 13D] Quantumsphere Acquisition Corp SEC Filing

Rhea-AI Filing Summary

Whiteowl Holdings LLC reported beneficial ownership of 3,126,650 Class A ordinary shares of Quantumsphere Acquisition Corp, representing approximately 27.41% of outstanding shares. The position comprises 2,898,000 founder shares (with 378,000 subject to forfeiture if the underwriters' over-allotment option is not exercised in full) and 228,650 ordinary shares issued as Private Placement Units purchased at $10.00 per unit. The Sponsor purchased the Placement Units for $2,286,500 from working capital and holds certain voting and lock-up commitments in favor of any proposed business combination. On July 25, 2025, 83.13% of the Sponsor's interest was transferred to Wealthwise Solutions LTD, making it the Sponsor's majority holder.

Positive

• Material ownership stake: Reporting Person beneficially owns 3,126,650 shares (27.41%), providing significant voting influence.
• Private Placement investment: Sponsor purchased 228,650 units at $10.00 per unit (aggregate $2,286,500) using working capital.
• Contractual commitments: Sponsor agreed to vote shares in favor of a business combination and accepted lock-up and indemnity provisions that support transaction certainty.
• Registration rights: Sponsor was granted demand and piggyback registration rights, providing potential future liquidity subject to customary conditions.

Negative

• Founder share forfeiture: 378,000 founder shares are subject to forfeiture if the underwriters' over-allotment option is not exercised in full, reducing Sponsor economics.
• Change in Sponsor control: Transfer of 83.13% of Sponsor interest to Wealthwise Solutions LTD alters the Sponsor's ownership and may affect governance or strategic intent.
• Lock-up restrictions: Sponsor agreed not to redeem Founder Shares or Placement Units in certain liquidation or vote scenarios, limiting Sponsor liquidity and flexibility.

Insights

Financial Analyst

TL;DR: Sponsor holds a material 27.41% stake with lock-up and voting commitments that support deal approvals.

The reporting shows Whiteowl Holdings LLC controls a substantial ownership stake in QUMSU through founder shares and private placement units, aligning significant voting power behind the issuer's potential business combination plans. The Sponsor's voting commitments and indemnity provisions reduce the likelihood of founder-share redemptions that could impede a transaction vote. The Private Placement Units were acquired for $2.29 million from working capital, and registration rights give the Sponsor pathways to liquidity subject to customary limitations. The transfer of 83.13% of Sponsor interest to Wealthwise Solutions LTD changes the Sponsor's ownership structure and could affect governance dynamics.

M&A Specialist

TL;DR: The Sponsor's commitments facilitate a smoother path to an initial business combination but ownership changes warrant monitoring.

The agreements described—including the Subscription Agreement amendments, Insider Letter voting and redemption restrictions, and the Registration Rights Agreement—create contractual support for completing a business combination by limiting Sponsor-driven redemptions and aligning votes. The conditional forfeiture of 378,000 founder shares ties certain economics to underwriter activity. The July 25, 2025 transfer making Wealthwise Solutions LTD the majority holder of the Sponsor is a notable change in the controlling interest of the Sponsor and should be reviewed for any strategic implications or related-party considerations in a deal context.

SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

SCHEDULE 13D

Under the Securities Exchange Act of 1934

Quantumsphere Acquisition Corp

(Name of Issuer)

Class A Ordinary Share, par value $0.0001 per share

(Title of Class of Securities)

G7387B106

(CUSIP Number)

Ping Zhang
1185 Avenue of the Americas, Suite 304
New York, NY, 10036
(212) 612-1400

(Name, Address and Telephone Number of Person Authorized to Receive Notices and Communications)

08/05/2025

(Date of Event Which Requires Filing of This Statement)

If the filing person has previously filed a statement on Schedule 13G to report the acquisition that is the subject of this Schedule 13D, and is filing this schedule because of §§ 240.13d-1(e), 240.13d-1(f) or 240.13d-1(g), check the following box.

The information required on the remainder of this cover page shall not be deemed to be "filed" for the purpose of Section 18 of the Securities Exchange Act of 1934 ("Act") or otherwise subject to the liabilities of that section of the Act but shall be subject to all other provisions of the Act (however, see the Notes).

SCHEDULE 13D

CUSIP No. G7387B106

1

Name of reporting person

Whiteowl Holdings LLC

2

Check the appropriate box if a member of a Group (See Instructions)

(a)
(b)

3

SEC use only

4

Source of funds (See Instructions)

OO

5

Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)

6

Citizenship or place of organization

DELAWARE

Number of Shares Beneficially Owned by Each Reporting Person With:

7	Sole Voting Power 3,126,650.00
8	Shared Voting Power 0.00
9	Sole Dispositive Power 3,126,650.00
10	Shared Dispositive Power 0.00

11

Aggregate amount beneficially owned by each reporting person

3,126,650.00

12

Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)

13

Percent of class represented by amount in Row (11)

27.41 %

14

Type of Reporting Person (See Instructions)

OO

Comment for Type of Reporting Person:

Includes (i) 2,898,000 ordinary shares of the Issuer, $0.0001 par value ("Founder Shares") as more fully described under the heading "Description of Securities--Founder Shares" in the Issuer's registration statement on Form S-1 (File No. 333-287672), and (ii) 228,650 ordinary shares of the Issuer underlying units (each unit consisting of one ordinary share and one right to receive one-seventh (1/7) of one ordinary share upon the consummation of the Issuer's initial business combination, acquired pursuant to a Private Placement Unit Purchase Agreement by and between Whiteowl Holdings LLC (the "Sponsor") and the Issuer. On July 25, 2025, the Sponsor and its member entered into the First Amendment to the Operating Agreement, whereby 83.13% of the Sponsor's interest was transferred to Wealthwise Solutions Ltd., making it the majority holder of the Sponsor.

SCHEDULE 13D

Item 1.	Security and Issuer
(a)	Title of Class of Securities: Class A Ordinary Share, par value $0.0001 per share
(b)	Name of Issuer: Quantumsphere Acquisition Corp
(c)	Address of Issuer's Principal Executive Offices: 1185 Avenue of the Americas, Suite 304, New York, NEW YORK , 10036.
Item 1 Comment: This Schedule 13D is filed on behalf of Whiteowl Holdings LLC, a limited liability company (the "Sponsor" or the "Reporting Person").
Item 2.	Identity and Background
(a)	This statement is filed by the Reporting Person. The Reporting Person is the holder of record of approximately 27.41% of the Issuer's outstanding Ordinary Shares based on the number of Ordinary Shares outstanding as of August 7, 2025.
(b)	The principal business address of the Reporting Person is 1185 Avenue of the Americas, Suite 304, New York, NY 10036.
(c)	The Reporting Person is the Sponsor of the Issuer in connection with the Issuer's initial public offering and potential business combination.
(d)	During the past five years, the Reporting Person has not been convicted in a criminal proceeding (excluding traffic violations or similar misdemeanors).
(e)	During the past five years, the Reporting Person has not been a party to any civil proceeding of a judicial or administrative body of competent jurisdiction that resulted in a judgment, decree, or final order enjoining future violations of, or prohibiting or mandating activities subject to, federal or state securities laws, or finding any violation with respect to such laws.
(f)	The Reporting Person is a Delaware limited liability company.
Item 3.	Source and Amount of Funds or Other Consideration
	The information set forth in Items 4 and 5 of this Schedule 13D are hereby incorporated by reference into this Item 3.
Item 4.	Purpose of Transaction
	In connection with the organization of the Issuer, on August 29, 2024, pursuant to a Subscription Agreement, the Issuer issued an aggregate of 2,875,000 ordinary shares as Founder Shares, to the Sponsor for an aggregate purchase price of $25,000. On May 6, 2025, our Sponsor surrendered 460,000 founder shares for no consideration to us for cancellation and as a result, our Sponsor held 2,415,000 founder shares as of May 6, 2025. On August 5, 2025, the Issuer and the Sponsor entered into the First Amendment to the Subscription Agreement, pursuant to which the purchased amount of shares was adjusted to 2,898,000 ordinary shares, of which 378,000 are subject to forfeiture if the underwriters' over-allotment option is not exercised in full. Simultaneously with the consummation of the Issuer's initial public offering, the Sponsor purchased 228,650 units ("Placement Units") of the Issuer at $10.00 per Placement Unit, as more fully described in Item 6 of this Schedule 13D, which information is incorporated herein by reference. Each Placement Unit consists of one ordinary share and one right to receive one-seventh (1/7) of one ordinary share upon the consummation of the Issuer's initial business combination (as described more fully in the Issuer's Final Prospectus dated August 7, 2025). On July 25, 2025, the Sponsor and its member entered into the First Amendment to the Operating Agreement, whereby 83.13% of the Sponsor's interest was transferred to Wealthwise Solutions LTD, making it the majority holder of the Sponsor. The Ordinary Shares owned by the Reporting Person have been acquired for investment purposes. The Reporting Person may make further acquisitions of the Ordinary Shares from time to time and, subject to certain restrictions, may dispose of any or all of the Ordinary Shares held by the Reporting Person at any time depending on an ongoing evaluation of the investment in such securities, prevailing market conditions, other investment opportunities and other factors, subject to certain lock-up restrictions. Except for the foregoing, the Reporting Person has no plans or proposals which relate to, or could result in, any of the matters referred to in paragraphs (a) and (c) through (j) of Item 4 of Schedule 13D. With respect to paragraph (b) of Item 4, the Issuer is a newly organized blank check company formed for the purpose of effecting a merger, capital stock exchange, asset acquisition, stock purchase, reorganization or similar business combination with one or more businesses. Under various agreements between the Issuer and the Reporting Person, the Reporting Person has agreed (A) to vote their shares in favor of any proposed business combination; (B) not to redeem any shares in connection with a shareholder vote (or tender offer) to approve (or in connection with) (i) a proposed initial business combination or (ii) an amendment to certain provisions of the Issuer's amended and restated memorandum and articles of association; and (C) not to redeem any Founder Shares or the Ordinary Shares comprising the Private Placement Units in connection with the liquidation of the Trust Account (as defined below) if the Issuer fails to complete an initial business combination within 15 months from the completion of its initial public offering. The Reporting Person may, at any time and from time to time, review or reconsider their position, change their purpose or formulate plans or proposals with respect to the Issuer.
Item 5.	Interest in Securities of the Issuer
(a)	he responses to Items 7 - 13 of the cover pages of this Schedule 13D are incorporated herein by reference. The aggregate number and percentage of Ordinary Shares beneficially or directly owned by the Reporting Person is based upon a total of 11,406,650 ordinary shares and outstanding as of August 7, 2025. The Reporting Person beneficially owns 3,126,650 Ordinary Shares, representing approximately 27.41% of the total issued and outstanding ordinary shares.
(b)	The responses to Items 7 - 13 of the cover pages of this Schedule 13D are incorporated herein by reference. The beneficial ownership of the Reporting Person is 3,126,650 Ordinary Shares, representing approximately 27.41% of total issued and outstanding Ordinary Shares.
(c)	The Reporting Person has not effected any transactions of the Issuer's Ordinary Shares during the 60 days preceding the date of this report, except as described in Item 6 of this Schedule 13D which information is incorporated herein by reference.
(d)	N/A
(e)	N/A
Item 6.	Contracts, Arrangements, Understandings or Relationships With Respect to Securities of the Issuer
	Securities Subscription Agreement between the Issuer and Sponsor On August 29, 2024, the Issuer and Sponsor entered into a Subscription Agreement, pursuant to which the Issuer issued an aggregate of 2,875,000 ordinary shares as Founder Shares, to the Sponsor for an aggregate purchase price of $25,000. On May 6, 2025, our Sponsor surrendered 460,000 founder shares for no consideration to us for cancellation and as a result, our Sponsor held 2,415,000 founder shares as of May 6, 2025. On August 5, 2025, the Issuer and the Sponsor entered into the First Amendment to the Subscription Agreement, pursuant to which the purchased amount of shares was adjusted to 2,898,000 ordinary shares, of which 378,000 are subject to forfeiture if the underwriters' over-allotment option is not exercised in full. The description of the First Amendment to the Subscription Agreement is qualified in its entirety by reference to the full text of such agreement, a copy of which was filed as Exhibit 10.5 to the Issuer's Form 8-K, filed by the Issuer with the SEC on August 7, 2025 (and is incorporated by reference herein as Exhibit 10.5). On July 25, 2025, the Sponsor and its member entered into the First Amendment to the Operating Agreement, whereby 83.13% of the Sponsor's interest was transferred to Wealthwise Solutions LTD, making it the majority holder of the Sponsor. Private Placement On August 5, 2025, simultaneously with the consummation of the Issuer's initial public offering, Whiteowl Holdings LLC (the "Reporting Person" or "Sponsor") purchased 228,650 units (the "Private Placement Units") of the Issuer at a price of $10.00 per unit, for an aggregate purchase price of $2,286,500. Each Private Placement Unit consists of one ordinary share, par value $0.0001 per share, and one right to receive one-seventh (1/7) of one ordinary share upon the consummation of the Issuer's initial business combination. The Reporting Person used funds from its working capital to purchase the Private Placement Units. Insider Letter On August 5, 2025, in connection with the IPO, the Issuer and the Sponsor entered into a letter agreement (the "Letter Agreement"). Pursuant to the Letter Agreement, the Sponsor agreed (A) to vote its Founder Shares, any Ordinary Shares underlying the Placement Units and any public shares (other than public shares purchased outside of a redemption offer which may not be voted in favor of approving the Business Combination transaction in accordance with the requirements of Rule 14e-5 under the Exchange Act and any SEC interpretations or guidance relating thereto) in favor of any proposed business combination, (B) not to propose an amendment to the Issuer's Amended and Restated Memorandum and Articles of Association that would modify the substance or timing of the Issuer's obligation to redeem the public shares if the Issuer has not consummated a business combination within 18 months from the completion of the initial public offering or any other provision relating to shareholders' rights or pre-initial business combination activity, (C) not to redeem any Founder Shares and any shares underlying the Placement Units into the right to receive cash from the Trust Account of the Issuer (as defined in the Insider Letter) in connection with a shareholder vote to approve the Issuer's proposed business combination or a vote to amend the provisions of the Issuer's Amended and Restated Memorandum and Articles of Association relating to shareholders' rights or pre-business combination activity and (D) that the Founder Shares and any Ordinary Shares underlying the Placement Units shall not participate in any liquidating distribution upon winding up if a business combination is not consummated. The Sponsor also agreed that in the event of the liquidation of the Trust Account, it will indemnify and hold harmless the Issuer against any and all loss, liability, claims, damage and expense whatsoever which the Issuer may become subject as a result of any claim by any vendor or other person who is owed money by the Issuer for services rendered or products sold to or contracted for the Issuer, or by any target business with which the Issuer has discussed entering into a transaction agreement, but only to the extent necessary to ensure that such loss, liability, claim, damage or expense does not reduce the amount of funds in the Trust Account; provided that such indemnity shall not apply if such vendor or prospective target business executes an agreement waiving any claims against the Trust Account. The description of the Insider Letter contained in this Schedule 13D is qualified in its entirety by reference to the full text of such agreement, a copy of which was filed by the Issuer as Exhibit 10.1 to the Form 8-K filed by the Issuer with the SEC on August 5, 2025, and is incorporated herein by reference as Exhibit 10.1. Registration Rights Agreement On August 5, 2025, in connection with the Issuer's initial public offering, the Issuer and Whiteowl Holdings LLC (the "Sponsor") entered into a registration rights agreement, pursuant to which the Sponsor was granted certain demand and "piggyback" registration rights. These rights are subject to customary conditions and limitations, including the right of the underwriters of an offering to limit the number of shares offered. The description of the registration rights agreement contained in this Schedule 13D is qualified in its entirety by reference to the full text of such agreement, a copy of which was filed by the Issuer as Exhibit 10.3 to the Form 8-K filed by the Issuer with the SEC on August 5, 2025, and is incorporated herein by reference as Exhibit 10.3.
Item 7.	Material to be Filed as Exhibits.
	Exhibit 1 (Letter Agreement) and Exhibit 2 (Registration Rights Agreement): both are dated August 5, 2025 and were filed with the Form 8-K filed August 7, 2025. https://www.sec.gov/Archives/edgar/data/2070900/000182912625005919/quantumsphereacq_ex10-1.htm https://www.sec.gov/Archives/edgar/data/2070900/000182912625005919/quantumsphereacq_ex10-3.htm Exhibit 3 (Securities Subscription Agreement/Amendment): dated March 9, 2025, filed with the Form 8-K filed August 14, 2025 (reporting August 7, 2025). https://www.sec.gov/Archives/edgar/data/2070900/000182912625005919/quantumsphereacq_ex10-5.htm

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.

Whiteowl Holdings LLC

Signature:	/s/ Ping Zhang
Name/Title:	Ping Zhang/Chief Executive Officer and Chairman
Date:	09/15/2025

FAQ

How many shares of Quantumsphere Acquisition Corp (QUMSU) does Whiteowl Holdings LLC beneficially own?

Whiteowl Holdings LLC beneficially owns 3,126,650 ordinary shares, representing approximately 27.41% of outstanding shares.

What comprises Whiteowl's ownership in QUMSU?

The stake includes 2,898,000 founder shares (with 378,000 subject to forfeiture) and 228,650 ordinary shares issued as Private Placement Units.

What did the Sponsor pay for the Private Placement Units?

The Sponsor purchased 228,650 units at $10.00 each, for an aggregate purchase price of $2,286,500, using working capital.

Did the Sponsor change ownership or control recently?

Yes. On July 25, 2025, 83.13% of the Sponsor's interest was transferred to Wealthwise Solutions LTD, making it the majority holder of the Sponsor.

Are there voting or redemption commitments by the Sponsor?

Yes. Under an Insider Letter, the Sponsor agreed to vote in favor of proposed business combinations and not to redeem Founder Shares or Placement Unit shares in specified vote or liquidation scenarios.