Arqit Quantum Inc. (ARQQ) received an amended Schedule 13G from Notion Capital III reporting beneficial ownership of 1,812,206 Ordinary Shares, representing 10.0% of the class. All shares are held of record by Liberum Wealth Limited for the account of Notion Capital III LP, including 124 shares held by Notion Platform Limited and 76,381 shares issuable upon conversion of Registered Direct Warrants at $19.50 per share, all after a Reverse Share Split. On June 26, 2026, Notion Capital III exercised in full 600,000 September 2024 Warrants at $2.50 per share, resulting in the issuance of 600,000 Ordinary Shares, and on June 24, 2026 it sold 58,263 Ordinary Shares from previously held shares. Notion Capital III reports shared voting and dispositive power over all 1,812,206 shares and no sole power.
Positive
None.
Negative
None.
Key Figures
Beneficially owned Ordinary Shares:1,812,206 sharesPercent of class:10.0%Shares outstanding basis:17,402,411 shares+4 more
7 metrics
Beneficially owned Ordinary Shares1,812,206 sharesShares beneficially owned by Notion Capital III as reported in the amendment
Percent of class10.0%Portion of Arqit Quantum’s Ordinary Shares beneficially owned by Notion Capital III
Shares outstanding basis17,402,411 sharesOrdinary Shares issued and outstanding as of May 19, 2026, used to calculate ownership percentage
September 2024 Warrants exercised600,000 warrants at $2.50 per shareExercised in full on June 26, 2026, resulting in 600,000 Ordinary Shares
Registered Direct Warrants76,381 warrants at $19.50 per shareEach warrant exercisable into one Ordinary Share, included in beneficial ownership
Shares sold58,263 sharesOrdinary Shares sold by Notion Capital III on June 24, 2026
Shared voting and dispositive power1,812,206 sharesShares over which Notion Capital III has shared voting and dispositive power
Key Terms
beneficially owned, Reverse Share Split, Registered Direct Warrants, securities purchase agreement, +1 more
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.
Reverse Share Splitfinancial
"Such share amounts include 124 Ordinary Shares held by Notion Platform Limited and reflect the Reverse Share Split."
A reverse share split is when a company reduces the number of its shares outstanding by combining multiple shares into one, effectively increasing the price of each share. For investors, this can help improve the company's image or meet stock exchange listing requirements, but it does not change the total value of their investment. It’s similar to turning many small pieces of a puzzle into fewer larger pieces—nothing new is added or lost, just rearranged.
Registered Direct Warrantsfinancial
"include 76,381 Ordinary Shares that could be obtained upon the conversion of 76,381 Registered Direct Warrants"
securities purchase agreementfinancial
"Registered Direct Warrants received in connection with the securities purchase agreement, dated September 8, 2023"
A securities purchase agreement is a written contract between a buyer and a seller outlining the terms for buying or selling financial assets such as stocks or bonds. It specifies details like the price, quantity, and conditions of the transaction, similar to a shopping list with agreed-upon terms. For investors, it provides clarity and legal protection when transferring ownership of these financial instruments.
Rule 13d-3(d)(1)(i)regulatory
"deemed outstanding for the reporting person pursuant to Rule 13d-3(d)(1)(i)."
FAQ
What percentage of Arqit Quantum Inc. (ARQQ) does Notion Capital III report owning?
Notion Capital III reports beneficial ownership of 10.0% of Arqit Quantum Inc.’s Ordinary Shares. This percentage is based on 17,402,411 Ordinary Shares outstanding as of May 19, 2026, plus 600,000 new shares from warrant exercise and 76,381 shares deemed outstanding from warrants.
How many Arqit Quantum (ARQQ) shares does Notion Capital III beneficially own?
Notion Capital III reports beneficial ownership of 1,812,206 Ordinary Shares of Arqit Quantum Inc. This total includes existing shares, 600,000 shares issued upon exercise of September 2024 Warrants, and 76,381 shares issuable upon exercise of Registered Direct Warrants.
What recent warrant exercise involving ARQQ did Notion Capital III report?
On June 26, 2026, Notion Capital III exercised in full 600,000 September 2024 Warrants, each giving the right to buy one Ordinary Share at $2.50 per share. This resulted in the issuance of 600,000 Ordinary Shares that are included in its reported holdings.
Did Notion Capital III sell any Arqit Quantum (ARQQ) shares recently?
Yes. On June 24, 2026, Notion Capital III sold 58,263 Ordinary Shares of Arqit Quantum Inc. from its previously held Ordinary Shares. These transactions are reflected in the updated beneficial ownership reported in the amendment.
What warrants tied to Arqit Quantum (ARQQ) does Notion Capital III still hold?
Notion Capital III’s reported holdings include 76,381 Ordinary Shares that could be obtained upon conversion of 76,381 Registered Direct Warrants, each exercisable at $19.50 per share, after giving effect to the Reverse Share Split.
Does Notion Capital III have sole or shared voting power over its ARQQ shares?
Notion Capital III reports 0 shares with sole voting or dispositive power and 1,812,206 shares with shared voting and shared dispositive power. The shares are held of record by Liberum Wealth Limited for the account of Notion Capital III LP.
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549
SCHEDULE 13G
UNDER THE SECURITIES EXCHANGE ACT OF 1934
(Amendment No. 1)
Arqit Quantum Inc.
(Name of Issuer)
Ordinary Shares
(Title of Class of Securities)
G0567U127
(CUSIP Number)
06/26/2026
(Date of Event Which Requires Filing of this Statement)
Check the appropriate box to designate the rule pursuant to which this Schedule is filed:
Rule 13d-1(b)
Rule 13d-1(c)
Rule 13d-1(d)
schemaVersion:
SCHEDULE 13G
CUSIP Number(s):
G0567U127
1
Names of Reporting Persons
Notion Capital III LP
2
Check the appropriate box if a member of a Group (see instructions)
(a)
(b)
3
Sec Use Only
4
Citizenship or Place of Organization
UNITED KINGDOM
Number of Shares Beneficially Owned by Each Reporting Person With:
5
Sole Voting Power
0.00
6
Shared Voting Power
1,812,206.00
7
Sole Dispositive Power
0.00
8
Shared Dispositive Power
1,812,206.00
9
Aggregate Amount Beneficially Owned by Each Reporting Person
1,812,206.00
10
Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)
11
Percent of class represented by amount in row (9)
10.0 %
12
Type of Reporting Person (See Instructions)
PN
SCHEDULE 13G
Item 1.
(a)
Name of issuer:
Arqit Quantum Inc.
(b)
Address of issuer's principal executive offices:
3 Orchard Place, London, X0, W1H 0BF.
Item 2.
(a)
Name of person filing:
Notion Capital III LP
(b)
Address or principal business office or, if none, residence:
91 Wimpole Street, London, W1G 0EF, United Kingdom
(c)
Citizenship:
United Kingdom
(d)
Title of class of securities:
Ordinary Shares
(e)
CUSIP No.:
G0567U127
Item 3.
If this statement is filed pursuant to §§ 240.13d-1(b) or 240.13d-2(b) or (c), check whether the person filing is a:
(a)
Broker or dealer registered under section 15 of the Act (15 U.S.C. 78o);
(b)
Bank as defined in section 3(a)(6) of the Act (15 U.S.C. 78c);
(c)
Insurance company as defined in section 3(a)(19) of the Act (15 U.S.C. 78c);
(d)
Investment company registered under section 8 of the Investment Company Act of 1940 (15 U.S.C. 80a-8);
(e)
An investment adviser in accordance with § 240.13d-1(b)(1)(ii)(E);
(f)
An employee benefit plan or endowment fund in accordance with § 240.13d-1(b)(1)(ii)(F);
(g)
A parent holding company or control person in accordance with § 240.13d-1(b)(1)(ii)(G);
(h)
A savings associations as defined in Section 3(b) of the Federal Deposit Insurance Act (12 U.S.C. 1813);
(i)
A church plan that is excluded from the definition of an investment company under section 3(c)(14) of the Investment Company Act of 1940 (15 U.S.C. 80a-3);
(j)
A non-U.S. institution in accordance with § 240.13d-1(b)(1)(ii)(J). If filing as a non-U.S. institution in accordance with § 240.13d-1(b)(1)(ii)(J),
please specify the type of institution:
(k)
Group, in accordance with Rule 240.13d-1(b)(1)(ii)(K).
Item 4.
Ownership
(a)
Amount beneficially owned:
1,812,206(1)(2) Ordinary Shares
(1) The share amounts in Item 4(a), (c)(ii), and (c)(iv) consist solely of Ordinary Shares of the Issuer that are held of record by Liberum Wealth Limited for the account of, and are beneficially owned by, Notion Capital III LP, and do not include any other securities of the Issuer that Liberum Wealth Limited may hold for its own account or for other clients. Such share amounts include 124 Ordinary Shares held by Notion Platform Limited and reflect the Reverse Share Split.
(2) The share amounts in Item 4(a), (c)(ii), and (c)(iv) include 76,381 Ordinary Shares that could be obtained upon the conversion of 76,381 Registered Direct Warrants received in connection with the securities purchase agreement, dated September 8, 2023, by and among the Issuer and certain purchasers, with each Registered Direct Warrant providing the right to purchase one Ordinary Share at a price of $19.50 per share, after reflecting the Reverse Share Split. On June 26, 2026, the reporting person exercised in full the 600,000 September 2024 Warrants received in connection with the securities purchase agreement, dated September 30, 2024, by and among the Issuer and certain purchasers, with each September 2024 Warrant providing the right to purchase one Ordinary Share at a price of $2.50 per share, resulting in the issuance of 600,000 Ordinary Shares, all of which are included in the share amounts in Item 4(a), (c)(ii), and (c)(iv). Separately, on June 24, 2026, the reporting person sold 58,263 Ordinary Shares from its previously held Ordinary Shares.
(b)
Percent of class:
10.0% (3)
(3) Percentage of class represented by amount in Item 4(a) is calculated based on 17,402,411 Ordinary Shares issued and outstanding as of May 19, 2026, as reported in the Issuer's prospectus supplement on Form 424B3 (Registration No. 333-259982) filed with the Securities and Exchange Commission on May 21, 2026, plus the 600,000 Ordinary Shares issued upon the exercise in full of the September 2024 Warrants, and after reflecting the Reverse Share Split, together with the 76,381 Ordinary Shares issuable upon exercise of the Registered Direct Warrants held by the reporting person that are deemed outstanding for the reporting person pursuant to Rule 13d-3(d)(1)(i).
(c)
Number of shares as to which the person has:
(i) Sole power to vote or to direct the vote:
0
(ii) Shared power to vote or to direct the vote:
1,812,206 (1)(2)
(1) The share amounts in Item 4(a), (c)(ii), and (c)(iv) consist solely of Ordinary Shares of the Issuer that are held of record by Liberum Wealth Limited for the account of, and are beneficially owned by, Notion Capital III LP, and do not include any other securities of the Issuer that Liberum Wealth Limited may hold for its own account or for other clients. Such share amounts include 124 Ordinary Shares held by Notion Platform Limited and reflect the Reverse Share Split.
(2) The share amounts in Item 4(a), (c)(ii), and (c)(iv) include 76,381 Ordinary Shares that could be obtained upon the conversion of 76,381 Registered Direct Warrants received in connection with the securities purchase agreement, dated September 8, 2023, by and among the Issuer and certain purchasers, with each Registered Direct Warrant providing the right to purchase one Ordinary Share at a price of $19.50 per share, after reflecting the Reverse Share Split. On June 26, 2026, the reporting person exercised in full the 600,000 September 2024 Warrants received in connection with the securities purchase agreement, dated September 30, 2024, by and among the Issuer and certain purchasers, with each September 2024 Warrant providing the right to purchase one Ordinary Share at a price of $2.50 per share, resulting in the issuance of 600,000 Ordinary Shares, all of which are included in the share amounts in Item 4(a), (c)(ii), and (c)(iv). Separately, on June 24, 2026, the reporting person sold 58,263 Ordinary Shares from its previously held Ordinary Shares.
(iii) Sole power to dispose or to direct the disposition of:
0
(iv) Shared power to dispose or to direct the disposition of:
1,812,206 (1)(2)
(1) The share amounts in Item 4(a), (c)(ii), and (c)(iv) consist solely of Ordinary Shares of the Issuer that are held of record by Liberum Wealth Limited for the account of, and are beneficially owned by, Notion Capital III LP, and do not include any other securities of the Issuer that Liberum Wealth Limited may hold for its own account or for other clients. Such share amounts include 124 Ordinary Shares held by Notion Platform Limited and reflect the Reverse Share Split.
(2) The share amounts in Item 4(a), (c)(ii), and (c)(iv) include 76,381 Ordinary Shares that could be obtained upon the conversion of 76,381 Registered Direct Warrants received in connection with the securities purchase agreement, dated September 8, 2023, by and among the Issuer and certain purchasers, with each Registered Direct Warrant providing the right to purchase one Ordinary Share at a price of $19.50 per share, after reflecting the Reverse Share Split. On June 26, 2026, the reporting person exercised in full the 600,000 September 2024 Warrants received in connection with the securities purchase agreement, dated September 30, 2024, by and among the Issuer and certain purchasers, with each September 2024 Warrant providing the right to purchase one Ordinary Share at a price of $2.50 per share, resulting in the issuance of 600,000 Ordinary Shares, all of which are included in the share amounts in Item 4(a), (c)(ii), and (c)(iv). Separately, on June 24, 2026, the reporting person sold 58,263 Ordinary Shares from its previously held Ordinary Shares.
Item 5.
Ownership of 5 Percent or Less of a Class.
Not Applicable
Item 6.
Ownership of more than 5 Percent on Behalf of Another Person.
Not Applicable
Item 7.
Identification and Classification of the Subsidiary Which Acquired the Security Being Reported on by the Parent Holding Company or Control Person.
Not Applicable
Item 8.
Identification and Classification of Members of the Group.
Not Applicable
Item 9.
Notice of Dissolution of Group.
Not Applicable
Item 10.
Certifications:
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.
Notion Capital III LP
Signature:
/s/ Ian Milbourn
Name/Title:
Ian Milbourn, Designated Member of Notion Capital Managers LLP, for and on behalf of Notion Capital III GP LLP, its general partner
