As of November 10, 2026, 5 holders' latest Schedule 13D or 13G filings report owning 5% or more of Quantinuum Inc. The largest reported stake is Honeywell International Inc.'s, at 79.1%. 7 filings are on record since June 22, 2026 (Schedule 13G, August 13, 2026).
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Key facts
- · Reporting person: BlackRock Portfolio Management LLC · Sole voting: 1,521,301 · Shared voting: 0 · Sole dispositive: 1,664,459 · Shared dispositive: 0 · SCHEDULE 13G/A, 2026-10-27
- · Reporting person: Citadel Advisors LLC · Sole voting: 0 · Shared voting: 2,299,997 · Sole dispositive: 0 · Shared dispositive: 2,299,997 · SCHEDULE 13G, 2026-10-06
- · Reporting person: Honeywell International Inc. · Sole voting: 95,998,655 · Shared voting: 28,630,074 · Sole dispositive: 95,998,655 · Shared dispositive: 28,630,074 · SCHEDULE 13G, 2026-08-13
- · Reporting person: Capital Research Global Investors · Sole voting: 1,754,325 · Shared voting: 0 · Sole dispositive: 1,754,325 · Shared dispositive: 0 · SCHEDULE 13G, 2026-08-12
- · Holder: BlackRock Portfolio Management LLC · Percent: 6.9% · SCHEDULE 13G
Quantinuum Inc has 7 Schedule 13D or 13G filings on record since 2026-06-22. 5 holders' latest filing reports 5% or more of class a stock. Each figure below is the holder's own, as filed, with the filing linked.
Holders
| Holder | Percent | Shares | Latest | Event date |
|---|---|---|---|---|
| Honeywell International Inc. | 79.1% | 124,628,729 | SCHEDULE 13G, 2026-08-13 | 2026-06-30 |
| 72% | 83,365,334 | SCHEDULE 13G, 2026-06-22 | 2026-06-04 | |
| Capital World Investors | 13.9% | 4,558,976 | SCHEDULE 13G, 2026-07-06 | 2026-06-30 |
| 7.3% | 2,403,427 | SCHEDULE 13G, 2026-10-06 | 2026-06-30 | |
| Capital Research Global Investors | 5.3% | 1,754,325 | SCHEDULE 13G, 2026-08-12 | 2026-06-30 |
| BlackRock Portfolio Management LLC | 4.5% | 1,664,459 | SCHEDULE 13G/A, 2026-10-27 | 2026-09-30 |
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Keep reading
More on Quantinuum Inc and the records around it.
Quantinuum Inc elsewhere on the record
Companies that share a holder
- Citadel Advisors LLC also filed stake reports on 58 other companies: REALLOYS INC. (Oct 2026), STARFIGHTERS SPACE, INC. (Oct 2026), Boundless Bio, Inc. (Aug 2026)
- Capital Research Global Investors also filed stake reports on 99 other companies: Royal Caribbean Cruises Ltd. (Oct 2026), Patria Investments Ltd. (Sep 2026), Arxis, Inc. (Aug 2026)
- BlackRock Portfolio Management LLC also filed stake reports on 117 other companies: AMERISAFE INC (Nov 2026), BlackRock ETF Trust (Nov 2026), iShares J.P. Morgan EM Local Currency Bond ETF (Nov 2026)
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Voting and dispositive power, as filed
| Reporting person | Sole voting | Shared voting | Sole dispositive | Shared dispositive | Filing |
|---|---|---|---|---|---|
| Honeywell International Inc. | 95,998,655 | 28,630,074 | 95,998,655 | 28,630,074 | SCHEDULE 13G, 2026-08-13 |
| Honeywell Holdings International Inc. | 0 | 28,630,074 | 0 | 28,630,074 | SCHEDULE 13G, 2026-08-13 |
| Cambridge Quantum Holdings Limited | 0 | 82,884,823 | 0 | 82,884,823 | SCHEDULE 13G, 2026-06-22 |
| CQ Invest I LLC | 0 | 531,720 | 0 | 531,720 | SCHEDULE 13G, 2026-06-22 |
| Ilyas Khan | 480,511 | 82,884,823 | 480,511 | 82,884,823 | SCHEDULE 13G, 2026-06-22 |
| Waseem Shiraz | 27,001 | 82,884,823 | 27,001 | 82,884,823 | SCHEDULE 13G, 2026-06-22 |
| Capital World Investors | 4,558,976 | 0 | 4,558,976 | 0 | SCHEDULE 13G, 2026-07-06 |
| Citadel Advisors LLC | 0 | 2,299,997 | 0 | 2,299,997 | SCHEDULE 13G, 2026-10-06 |
| Citadel Advisors Holdings LP | 0 | 2,299,997 | 0 | 2,299,997 | SCHEDULE 13G, 2026-10-06 |
| Citadel GP LLC | 0 | 2,299,997 | 0 | 2,299,997 | SCHEDULE 13G, 2026-10-06 |
| Citadel Securities LLC | 0 | 103,430 | 0 | 103,430 | SCHEDULE 13G, 2026-10-06 |
| Citadel Securities Group LP | 0 | 103,430 | 0 | 103,430 | SCHEDULE 13G, 2026-10-06 |
| Citadel Securities GP LLC | 0 | 103,430 | 0 | 103,430 | SCHEDULE 13G, 2026-10-06 |
| Kenneth Griffin | 0 | 2,403,427 | 0 | 2,403,427 | SCHEDULE 13G, 2026-10-06 |
| Capital Research Global Investors | 1,754,325 | 0 | 1,754,325 | 0 | SCHEDULE 13G, 2026-08-12 |
| BlackRock Portfolio Management LLC | 1,521,301 | 0 | 1,664,459 | 0 | SCHEDULE 13G/A, 2026-10-27 |
The latest filing identifies Quantinuum Inc by CUSIP 74768A104 and gives its principal executive office as 303 S Technology Court, Broomfield, CO 80021 (SCHEDULE 13G/A, 2026-10-27).
Timeline
| Filed | Holder | Percent | Filing |
|---|---|---|---|
| 2026-06-22 | Ilyas Khan | 72% | SCHEDULE 13G |
| 2026-07-06 | Capital World Investors | 13.9% | SCHEDULE 13G |
| 2026-07-17 | BlackRock Portfolio Management LLC | 6.9% | SCHEDULE 13G |
| 2026-08-12 | Capital Research Global Investors | 5.3% | SCHEDULE 13G |
| 2026-08-13 | Honeywell International Inc. | 79.1% | SCHEDULE 13G |
| 2026-10-06 | Kenneth Griffin | 7.3% | SCHEDULE 13G |
| 2026-10-27 | BlackRock Portfolio Management LLC | 4.5% | SCHEDULE 13G/A |
Questions about who owns Quantinuum Inc
Who owns Quantinuum Inc?
On this page, 5 holders' latest ownership filings report 5% or more of Quantinuum Inc: Honeywell International Inc. (79.1%, Schedule 13G, filed 2026-08-13), Ilyas Khan (72%, Schedule 13G, filed 2026-06-22), Capital World Investors (13.9%, Schedule 13G, filed 2026-07-06), Kenneth Griffin (7.3%, Schedule 13G, filed 2026-10-06) and Capital Research Global Investors (5.3%, Schedule 13G, filed 2026-08-12).
Who are the largest shareholders of Quantinuum Inc?
By the share each holder's latest filing reports, the largest holders of Quantinuum Inc on this page are Honeywell International Inc. (79.1%), Ilyas Khan (72%) and Capital World Investors (13.9%).
When did Honeywell International Inc. buy into Quantinuum Inc?
The filings give report dates, not purchase dates. The earliest filing from Honeywell International Inc. on this page is the Schedule 13G, filed 2026-08-13, reporting 79.1%.
Is this an audit or a full list?
Neither. The ownership list on this page covers only Schedule 13D and 13G filings, which holders make once they own 5% or more of a class of shares (an amendment can report a stake that has since fallen below 5%); 7 such filings are shown here. It is not an audit and not a full cap table: holders who never reached 5% are not listed, and a stake can change after its latest filing.
Also on the record for Quantinuum Inc
| Date | Record | Figure | Our page | Source |
|---|---|---|---|---|
| June 5, 2026 | IPO filing, Form 424B4 | $60 a share | IPO filings | Source |
| June 1, 2026 | IPO filing, Form S-1/A | — | IPO filings | Source |
| May 26, 2026 | IPO filing, Form S-1/A | — | IPO filings | Source |
| May 8, 2026 | IPO filing, Form S-1 | — | IPO filings | Source |
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Where this comes from
Anyone who comes to own more than 5% of a class of a listed company's voting shares has to tell the SEC. A holder who may seek to change or influence the company files Schedule 13D, and has to say in Item 4, "Purpose of Transaction", what it intends to do. A holder with no such intent, such as many index and passive funds, may file the shorter Schedule 13G. Both are amended when the stake changes, including when it falls below 5%.
Every row here is one of those filings, linked to the filing itself. Percentages and share counts are exactly as the holder filed them, for the holder the filing names; an amendment showing a lower figure is shown as filed. Item 4 text is quoted word for word. Where a 13D's Item 4 contains a sentence stating a definite intent to influence the company, that sentence is marked and quoted; the page does not describe the holder or its motives beyond the words it filed. Nothing here is investment advice.