SCHEDULE 13D/A Filed 2026-11-05 Event 2026-11-03 SEC 0001213900-26-116500 →

You Harry L. → Horizon Quantum Holdings Ltd. HQWWW

Stake: 7.40% Shares: 2,655,028 CUSIP: Y4000A102 Class: Class A Ordinary Shares

Composite Decision Signal · PASS (LOW BASE-RATE EDGE) Conviction Score: 23/100 · Filer 90d Win Rate: 0% · Hist. 90d Edge: +0.0%

Active Schedule 13D filer baseline
Short interest building (+118.2% vs prior settlement)

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.

Cross-References

Insider Activity (last 365d)

22 transactions

12 buys · 4 sales · 4 awards/exercises

Issuer Cluster

4 13D/G filings on this issuer

3 other filings besides this one

Filer Track Record

3 filings by this filer

2 other filings in the data moat

Short Interest · settle 2026-10-15

DTC 2.35

24,327 shares short · +118.2% vs prior

Form 4 Insider Transactions · last 365d

Date	Insider	Role	Type	Shares	Price	Value
2026-11-03	You Harry L.	director, 10%+ owner	J	1,163,484	—	—
2026-11-03	You Harry L.	director, 10%+ owner	J	1,442,330	$11.50	$16.59M
2026-09-12	Fitzsimons Catherine Michele	officer	Option exercise	2,148	—	—
2026-09-12	Fitzsimons Catherine Michele	officer	Disposition	1,122	$15.22	$17K
2026-09-12	Gould Greg	officer	Option exercise	3,437	—	—
2026-09-12	Gould Greg	officer	Disposition	1,272	$15.22	$19K
2026-09-12	Tan Si-Hui	officer	Option exercise	5,728	—	—
2026-09-12	Tan Si-Hui	officer	Disposition	2,991	$15.22	$46K
2026-09-12	Fitzsimons Joseph Francis	director, officer, 10%+ owner	Option exercise	14,321	—	—
2026-09-12	Fitzsimons Joseph Francis	director, officer, 10%+ owner	Disposition	3,438	$15.22	$52K
2026-08-20	Tan Si-Hui	officer	Award	3,600	—	—
2026-06-12	Fitzsimons Catherine Michele	officer	Award	34,372	—	—
2026-06-12	Gould Greg	officer	Award	54,995	—	—
2026-06-12	Tan Si-Hui	officer	Award	91,659	—	—
2026-06-12	Fitzsimons Joseph Francis	director, officer, 10%+ owner	Award	229,148	—	—
2026-03-19	Lambert Danielle	director	Buy	84,602	$11.82	$1000K
2026-03-19	Tan Si-Hui	officer	Award	500,000	$0.15	$75K
2026-03-19	Gould Greg	officer	Award	285,300	$5.13	$1.46M
2026-03-19	Fitzsimons Joseph Francis	director, officer, 10%+ owner	Award	19,744,585	—	—
2026-03-19	You Harry L.	director, 10%+ owner	Award	1,163,484	—	—
2026-03-19	You Harry L.	director, 10%+ owner	Award	2,884,660	$11.50	$33.17M
2026-03-19	Tan Si-Hui	officer	Award	55,000	$2.88	$158K

Other 13D/G Filings on Horizon Quantum Holdings Ltd.

Filed	Form	Filer	Stake	Shares
2026-07-09	SCHEDULE 13D	Peak XV Partners Seed Investment	20.30%	6,468,999	view →
2026-06-25	SCHEDULE 13G	ICS OPPORTUNITIES, LTD.	—	—	view →
2026-04-01	SCHEDULE 13D	IonQ, Inc.	13.30%	4,230,118	view →

Other Filings by You Harry L.

Filed	Form	Issuer	Stake	Shares
2026-06-09	SCHEDULE 13D/A	Rain Enhancement Technologies Holdco, Inc. RAINW	—	4,522,347	view →
2025-01-31	SCHEDULE	Rain Enhancement Technologies Holdco, Inc. RAINW	32.30%	2,909,444	view →

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