# EDGAR Filing Document

**Accession Number:** 0001432602
**File Stem:** 0001829126-26-002585
**Filing Date:** 2026-3
**Character Count:** 5486
**Document Hash:** eadd20b1df7b7bb44e9806c122bd3d97
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001829126-26-002585.hdr.sgml**: 20260320

**ACCESSION NUMBER**: 0001829126-26-002585

**CONFORMED SUBMISSION TYPE**: 3

**PUBLIC DOCUMENT COUNT**: 1

**CONFORMED PERIOD OF REPORT**: 20260319

**FILED AS OF DATE**: 20260320

**DATE AS OF CHANGE**: 20260320

**REPORTING-OWNER**: 

**OWNER DATA:**
- **COMPANY CONFORMED NAME:** You Harry L.
- **CENTRAL INDEX KEY:** 0001432602

**ORGANIZATION NAME:**

**FILING VALUES:**
- **FORM TYPE:** 3
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 001-43203
- **FILM NUMBER:** 26778611

**MAIL ADDRESS:**
- **STREET 1:** 3421 HILLVIEW AVENUE
- **CITY:** PALO ALTO
- **STATE:** CA
- **ZIP:** 94304
**ISSUER**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** Horizon Quantum Holdings Ltd.
- **CENTRAL INDEX KEY:** 0002088256
- **STANDARD INDUSTRIAL CLASSIFICATION:** SERVICES-COMPUTER PROGRAMMING SERVICES [7371]
- **ORGANIZATION NAME:** 06 Technology
- **EIN:** 000000000
- **STATE OF INCORPORATION:** U0
- **FISCAL YEAR END:** 1231

**BUSINESS ADDRESS:**
- **ADDRESS IS A NON US LOCATION:** YES
- **STREET 1:** ALICE@MEDIAOPOLIS
- **STREET 2:** 29 MEDIA CIRCLE #05-22
- **CITY:** SINGAPORE
- **PROVINCE COUNTRY:** U0
- **ZIP:** 138565
- **BUSINESS PHONE:** 6581015024

**MAIL ADDRESS:**
- **ADDRESS IS A NON US LOCATION:** YES
- **STREET 1:** ALICE@MEDIAOPOLIS
- **STREET 2:** 29 MEDIA CIRCLE #05-22
- **CITY:** SINGAPORE
- **PROVINCE COUNTRY:** U0
- **ZIP:** 138565

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** Horizon Quantum Holdings Pte. Ltd.
- **DATE OF NAME CHANGE:** 20251230

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** Rose Holdco Pte. Ltd.
- **DATE OF NAME CHANGE:** 20250924

### UNITED STATES SECURITIES AND EXCHANGE COMMISSION
**Washington, D.C. 20549**

## FORM 3

### INITIAL STATEMENT OF BENEFICIAL OWNERSHIP OF SECURITIES

[ ] Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

---

| | | |
|:---|:---|:---|
| **1. Name and Address of Reporting Person**<sup>*</sup><br>You Harry L.<br><sub>(Last) (First) (Middle)</sub><br>1180 NORTH TOWN CENTER DRIVE<br>SUITE 100<br><sub>(Street)</sub><br>LAS VEGAS, NV 89144<br><sub>(City) (State) (Zip)</sub> | **3. Issuer Name and Ticker or Trading Symbol**<br>Horizon Quantum Holdings Ltd. [ HQ ] | **5. If Amendment, Date of Original Filed (Month/Day/Year)**<br>  |
| **2. Date of Event Requiring Statement (Month/Day/Year)**<br>2026-03-19 | **4. Relationship of Reporting Person(s) to Issuer**<br>(Check all applicable)<br>[X] Director   [ ] 10% Owner<br>[ ] Officer (give title below)   [ ] Other (specify below)<br>_ _ | **6. Individual or Joint/Group Filing (Check Applicable Line)**<br>[X] Form filed by One Reporting Person<br>[ ] Form filed by More than One Reporting Person |

---

## Table I - Non-Derivative Securities Beneficially Owned

---

|  |  |  |  |
| --- | --- | --- | --- |
| 1. Title of Security | 2. Amount of Securities Beneficially Owned | 3. Ownership Form | 4. Nature of Indirect Beneficial Ownership |
| Class A Ordinary Shares | 49214<sup>(1)</sup> | D |  |

---

## Table II - Derivative Securities Beneficially Owned

---

|  |  |  |  |  |  |  |  |
| --- | --- | --- | --- | --- | --- | --- | --- |
| 1. Title of Derivative Security | 2. Date Exercisable and Expiration Date (Month/Day/Year) | 2. Date Exercisable and Expiration Date (Month/Day/Year) | 3. Title and Amount of Underlying Securities | 3. Title and Amount of Underlying Securities | 4. Conversion or Exercise Price | 5. Ownership Form | 6. Nature of Indirect Beneficial Ownership |
| 1. Title of Derivative Security | Date Exercisable | Expiration Date | Title | Amount or Number of Shares | 4. Conversion or Exercise Price | 5. Ownership Form | 6. Nature of Indirect Beneficial Ownership |
|  |  |  |  |  |  |  |  |

---

### Footnotes:

(1) Prior to the closing of the business combination (the "Business Combination") among Horizon Quantum Holdings Ltd. (the "Issuer"), Horizon Quantum Computing Pte. Ltd. ("Horizon"), and dMY Squared Technology Group, Inc. ("DMY"), these Class A ordinary shares of the Issuer were issued pursuant to the terms of a Simple Agreement for Future Equity ("SAFE") entered into between the reporting person and Horizon and the terms of the Business Combination Agreement, dated as of September 9, 2025, by and among the Issuer, Horizon, and DMY upon the conversion of the SAFE.

**Remarks:**
As of March 19, 2026, in connection with the consummation of the Business Combination, the Issuer became the successor to DMY.

Due to the Issuer's status as a foreign private issuer pursuant to Rule 3a12-3(b) under the Act, the Reporting Person's transactions in the Issuer's equity securities are exempt from Sections 16(b) and 16(c) of the Act.

**Signature:** /s/ Harry L. You  
**Date:** 2026-03-20

### Remarks:

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.

* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).

** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).

Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.

**Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.**