Arqit Quantum director proposes 127-share sale

The shares came from restricted stock vesting, and the proposed sale includes an amount to cover a resulting tax obligation.

Rhea-AI Filing Summary

Arqit Quantum Inc. director Garth Ritchie reported a proposed sale of 127 common shares, with an approximate sale date of October 5, 2026, and an aggregate market value of $3,020.66. The shares are identified as acquired through restricted stock vesting on October 2, 2026. Ritchie stated that the sale includes an amount necessary to cover a tax obligation resulting from settlement of a vested equity award distribution.

Key Figures

Proposed sale: 127 common shares Aggregate market value: $3,020.66 Shares outstanding: 15,291,767 shares +2 more

5 metrics

Proposed sale 127 common shares Approximate sale date: October 5, 2026

Aggregate market value $3,020.66 Proposed sale

Shares outstanding 15,291,767 shares Issuer shares outstanding listed in the securities information

Prior sales 121 common shares Reported sold on October 2, 2026, during the prior three months

Reported value of prior sales $2,961.39 Reported sales during the prior three months

Key Terms

Rule 144, Restricted Stock Vesting, vested equity award distribution

3 terms

Rule 144 regulatory

"See the definition of "person" in paragraph (a) of Rule 144"

Rule 144 is a U.S. securities regulation that sets conditions under which restricted or insider-held shares can be legally resold to the public, such as required holding periods, availability of public information, limits on how much can be sold at once, and certain filing requirements. For investors it matters because it determines when previously locked-up shares can enter the market — like a release valve that can increase supply, affect share price, and signal insider intent.

Restricted Stock Vesting financial

"Nature of acquisition: Restricted Stock Vesting"

Restricted stock vesting is the timetable and conditions under which shares granted to employees or insiders become fully owned and can be sold, typically requiring continued work or meeting performance goals. It matters to investors because large blocks of shares can become tradable at once, which can change share supply and price, and because vesting aligns insiders’ incentives with the company’s long‑term performance—think of it like a timed unlock that both rewards and locks in key people.

vested equity award distribution financial

"settlement of a vested equity award distribution"

FAQ

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

How many ARQQ shares did director Garth Ritchie plan to sell?

Garth Ritchie reported a proposed sale of 127 common shares, with an approximate sale date of October 5, 2026, and an aggregate market value of $3,020.66.

How many shares did Garth Ritchie sell in the three months before the ARQQ notice?

The notice lists 121 common shares sold on October 2, 2026, for $2,961.39 during the prior three months.

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

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Available on EDGAR 10/05/2026 - 03:26 PM Accepted by SEC EDGAR 10/05/2026 - 03:25 PM Learn about SEC filing dates

Form 144 Filer Information	UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 144 NOTICE OF PROPOSED SALE OF SECURITIES PURSUANT TO RULE 144 UNDER THE SECURITIES ACT OF 1933
FORM 144

144: Filer Information

Filer CIK	0001840684
Filer CCC	XXXXXXXX
Is this a LIVE or TEST Filing?	LIVE TEST
Submission Contact Information
Name
Phone
E-Mail Address

144: Issuer Information

Name of Issuer	Arqit Quantum Inc.
SEC File Number	001-40777
Address of Issuer	3 ORCHARD PLACE LONDON UNITED KINGDOM SW1H 0BF
Phone	44 203 91 70155
Name of Person for Whose Account the Securities are To Be Sold	Ritchie Garth
See the definition of "person" in paragraph (a) of Rule 144. Information is to be given not only as to the person for whose account the securities are to be sold but also as to all other persons included in that definition. In addition, information shall be given as to sales by all persons whose sales are required by paragraph (e) of Rule 144 to be aggregated with sales for the account of the person filing this notice.
Relationship to Issuer	Director

144: Securities Information

Title of the Class of Securities To Be Sold	Name and Address of the Broker	Number of Shares or Other Units To Be Sold	Aggregate Market Value	Number of Shares or Other Units Outstanding	Approximate Date of Sale	Name the Securities Exchange
Common	Fidelity Brokerage Services LLC 900 Salem Street Smithfield RI 02917	127	3020.66	15291767	10/05/2026	NASDAQ

Furnish the following information with respect to the acquisition of the securities to be sold and with respect to the payment of all or any part of the purchase price or other consideration therefor:

144: Securities To Be Sold

Title of the Class	Date you Acquired	Nature of Acquisition Transaction	Name of Person from Whom Acquired	Is this a Gift?	Date Donor Acquired	Amount of Securities Acquired	Date of Payment	Nature of Payment *
Common	10/02/2026	Restricted Stock Vesting	Issuer			127	10/02/2026	Compensation

* If the securities were purchased and full payment therefor was not made in cash at the time of purchase, explain in the table or in a note thereto the nature of the consideration given. If the consideration consisted of any note or other obligation, or if payment was made in installments describe the arrangement and state when the note or other obligation was discharged in full or the last installment paid.

Furnish the following information as to all securities of the issuer sold during the past 3 months by the person for whose account the securities are to be sold.

144: Securities Sold During The Past 3 Months

Name and Address of Seller	Title of Securities Sold	Date of Sale	Amount of Securities Sold	Gross Proceeds
Garth Ritchie 3 Orchard Place London X0 SW1H 0BF	Common	10/02/2026	121	2961.39

144: Remarks and Signature

Remarks	Sale includes an amount necessary to cover a tax obligation resulting from the settlement of a vested equity award distribution.
Date of Notice	10/05/2026
ATTENTION:
The person for whose account the securities to which this notice relates are to be sold hereby represents by signing this notice that he does not know any material adverse information in regard to the current and prospective operations of the Issuer of the securities to be sold which has not been publicly disclosed. If such person has adopted a written trading plan or given trading instructions to satisfy Rule 10b5-1 under the Exchange Act, by signing the form and indicating the date that the plan was adopted or the instruction given, that person makes such representation as of the plan adoption or instruction date.
Signature	/s/ Jared Cook, as a duly authorized representative of Fidelity Brokerage Services LLC, as attorney-in-fact for Garth Ritchie
ATTENTION: Intentional misstatements or omission of facts constitute Federal Criminal Violations (See 18 U.S.C. 1001)