Horizon Quantum: Harry L. You reports 7.4% stake

The reported 7.4% ownership calculation uses 34,227,495 Class A ordinary shares outstanding as of June 30, 2026.

Available on EDGAR 11/05/2026 - 06:32 PM EST Accepted by SEC EDGAR 11/05/2026 - 06:28 PM EST Learn about SEC filing dates

Rhea-AI Filing Summary

Horizon Quantum Holdings Ltd. (HQ) reported that dMY Squared Sponsor, LLC made a pro rata in-kind distribution for no consideration on November 3, 2026, transferring 1,163,484 Class A ordinary shares and 2,844,660 warrants to its members. Harry L. You, the Sponsor’s managing member, received 1,163,484 shares and 1,442,330 warrants and now holds them directly.

Harry L. You reported beneficial ownership of 2,655,028 shares, or 7.4%; the ownership breakdown lists 1,212,698 Class A ordinary shares and 1,422,330 shares issuable upon warrants. The transaction description’s 1,442,330 warrants received differs from the 1,422,330 warrant shares in that breakdown. The percentage calculation uses 34,227,495 Class A ordinary shares outstanding as of June 30, 2026.

Filing Explained

The amendment reports that after the November 3 distribution, dMY Squared Sponsor has zero beneficial ownership of Horizon Quantum shares, leaving no reported beneficial stake at the sponsor; Harry L. You’s position is reported separately.

Key Figures

Class A ordinary shares distributed: 1,163,484 shares Warrants distributed: 2,844,660 warrants Warrants received by Harry L. You: 1,442,330 warrants +4 more

7 metrics

Class A ordinary shares distributed 1,163,484 shares Pro rata in-kind distribution on November 3, 2026

Warrants distributed 2,844,660 warrants Pro rata in-kind distribution on November 3, 2026

Warrants received by Harry L. You 1,442,330 warrants Distribution description

Beneficial ownership 2,655,028 shares Reported aggregate amount beneficially owned by Harry L. You

Class A ordinary shares issuable upon warrants 1,422,330 shares Included in the beneficial-ownership breakdown

Ownership percentage 7.4% Reported for Harry L. You

Class A ordinary shares outstanding 34,227,495 shares As of June 30, 2026

Key Terms

pro rata in-kind distribution, beneficially owned, sole dispositive power, issuable upon the exercise of warrants

4 terms

pro rata in-kind distribution financial

"pro rata in-kind distribution of 1,163,484 Class A ordinary shares"

beneficially owned financial

"Aggregate amount beneficially owned by each reporting person"

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 financial

"Sole Dispositive Power 2,655,028.00"

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.

issuable upon the exercise of warrants financial

"Class A Ordinary Shares issuable upon the exercise of warrants"

FAQ

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

What did dMY Squared Sponsor distribute in HQ?

On November 3, 2026, dMY Squared Sponsor, LLC distributed 1,163,484 Class A ordinary shares and 2,844,660 warrants to its members pro rata for no consideration. Harry L. You, the Sponsor’s managing member, received 1,163,484 shares and 1,442,330 warrants and holds them directly.

How many HQ shares did Harry L. You beneficially own?

Harry L. You reported beneficial ownership of 2,655,028 shares, or 7.4%. The ownership breakdown lists 1,212,698 Class A ordinary shares and 1,422,330 shares issuable upon warrants; the distribution description separately says he received 1,442,330 warrants.

What share count supports Harry L. You’s reported HQ ownership percentage?

The calculation used 34,227,495 Class A ordinary shares outstanding as of June 30, 2026. Shares subject to his warrants were deemed outstanding if the warrants were currently exercisable or would become exercisable within 60 days of the report date.

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

See more from StockTitan in Google Search and AI answers. Adds StockTitan as a preferred source · opens Google

Add on Google Not now

SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

SCHEDULE 13D

Under the Securities Exchange Act of 1934

(Amendment No. 1)

Horizon Quantum Holdings Ltd.

(Name of Issuer)

Class A Ordinary Shares

(Title of Class of Securities)

Y4000A102

(CUSIP Number)

Harry L. You
1180 North Town Center Drive, Suite 100
Las Vegas, NV, 89144
(702) 781-4313

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

11/03/2026

(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).

schemaVersion:

SCHEDULE 13D

CUSIP Number(s): Y4000A102

1

Name of reporting person

Harry L. You

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

UNITED STATES

Number of Shares Beneficially Owned by Each Reporting Person With:

7	Sole Voting Power 2,655,028.00
8	Shared Voting Power 0.00
9	Sole Dispositive Power 2,655,028.00
10	Shared Dispositive Power 0.00

11

Aggregate amount beneficially owned by each reporting person

2,655,028.00

12

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

13

Percent of class represented by amount in Row (11)

7.4 %

14

Type of Reporting Person (See Instructions)

IN

Comment for Type of Reporting Person:

Note to Row 7, 9 and 11: Includes (i) 1,212,698 Class A ordinary shares ("Class A Ordinary Shares"), of Horizon Quantum Holdings Ltd. (the "Issuer") and (ii) 1,422,330 Class A Ordinary Shares issuable upon the exercise of warrants of the Issuer. Note to Row 13: Based on an aggregate of 34,227,495 Class A Ordinary Shares outstanding as of June 30, 2026, as reported in the unaudited condensed consolidated interim financial statements of the Issuer filed as Exhibit 99.1 to the Issuer's current report on Form 6-K furnished to the U.S. Securities and Exchange Commission on August 4, 2026. In computing the number of shares beneficially owned by a person and the percentage ownership of that person, all shares subject to warrants held by such person were deemed outstanding if such warrants are currently exercisable or will become exercisable within 60 days of the date of this report. These shares were not deemed outstanding, however, for the purpose of computing the percentage ownership of any other person.

SCHEDULE 13D

CUSIP Number(s): Y4000A102

1

Name of reporting person

dMY Squared Sponsor, 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 0.00
8	Shared Voting Power 0.00
9	Sole Dispositive Power 0.00
10	Shared Dispositive Power 0.00

11

Aggregate amount beneficially owned by each reporting person

0.00

12

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

13

Percent of class represented by amount in Row (11)

0.0 %

14

Type of Reporting Person (See Instructions)

OO

Comment for Type of Reporting Person:

Note to Row 13: Based on an aggregate of 34,227,495 Class A Ordinary Shares outstanding as of June 30, 2026, as reported in the unaudited condensed consolidated interim financial statements of the Issuer filed as Exhibit 99.1 to the Issuer's current report on Form 6-K furnished to the U.S. Securities and Exchange Commission on August 4, 2026. In computing the number of shares beneficially owned by a person and the percentage ownership of that person, all shares subject to warrants held by such person were deemed outstanding if such warrants are currently exercisable or will become exercisable within 60 days of the date of this report. These shares were not deemed outstanding, however, for the purpose of computing the percentage ownership of any other person.

SCHEDULE 13D

Item 1.	Security and Issuer
(a)	Title of Class of Securities: Class A Ordinary Shares
(b)	Name of Issuer: Horizon Quantum Holdings Ltd.
(c)	Address of Issuer's Principal Executive Offices: 29 Media Cir. #05-22, Singapore, SINGAPORE , 138565.
Item 1 Comment: This Amendment No. 1 (the "Amendment") to the Schedule 13D (the "Schedule 13D") originally filed with the United States Securities and Exchange Commission ("SEC") on March 20, 2026, by Harry L. You and dMY Squared Sponsor, LLC ("dMY Sponsor"), is being filed to report the pro rata in-kind distribution of Class A Ordinary Shares and warrants exercisable for Class A Ordinary Shares of the Issuer ("Warrants") by dMY Sponsor. Capitalized terms used but not defined herein shall have the meanings ascribed to them in the Schedule 13D. The information set forth in response to each separate Item below shall be deemed to be a response to all Items where such information is relevant. Items 3 and 4 to the Schedule 13D are supplementally amended as follows, and Item 5 to the Schedule 13D is amended and restated as follows.
Item 3.	Source and Amount of Funds or Other Consideration
	To the extent required by Item 3, the information contained in Item 4 is incorporated herein by reference.
Item 4.	Purpose of Transaction
	Item 4 of Schedule 13D is hereby amended and supplemented by adding the following: On November 3, 2026, the Sponsor made a pro rata in-kind distribution of 1,163,484 Class A Ordinary Shares and 2,844,660 Warrants to its members for no consideration. Harry L. You, the managing member of the Sponsor, received 1,163,484 of such Class A Ordinary Shares and 1,442,330 of such Warrants in such pro rata in-kind distribution, and now holds such securities directly.
Item 5.	Interest in Securities of the Issuer
(b)	For each Reporting Person, the number of shares as to which there is sole power to vote or to direct the vote, shared power to vote or to direct the vote, sole power to dispose or to direct the disposition, or shared power to dispose or to direct the disposition are set forth on rows 7 through 11 and row 13 of the cover pages of this Schedule 13D and are incorporated herein by reference.
(c)	Except for the transactions described in Item 4 of this Schedule 13D, the Reporting Persons have not engaged in any transaction during the past 60 days involving the Class A Ordinary Shares of the Issuer.
(d)	To the best knowledge of the Reporting Persons, no one other than the Reporting Persons, or the affiliates of the Reporting Persons, is known to have the right to receive, or the power to direct the receipt of, dividends from, or proceeds from the sale of, the Class A Ordinary Shares reported herein as beneficially owned by the Reporting Persons.
(e)	Not applicable

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.

Harry L. You

Signature:	/s/ Harry L. You
Name/Title:	Harry L. You, Self
Date:	11/05/2026

dMY Squared Sponsor, LLC

Signature:	/s/ Harry L. You
Name/Title:	Harry L. You, Managing Member
Date:	11/05/2026