SEC Form 4 · accession 0001104659-26-080395

Arqit Quantum Inc. · ARQQ

Statement of changes in beneficial ownership, as filed. Original on EDGAR ↗

Reporting owner

d'Ovidio Manfredi Lefebvre

Director

Period of report

Jun 30, 2026

Accepted (ET)

Jul 2, 2026 · 4:51 pm EDT

Rule 10b5-1 plan

box not checked

Issuer CIK

0001859690

Table I — non-derivative securities

Security	Date	Code	Shares	Price	A/D	Owned after	D/I	Nature of ownership
Ordinary Shares^F1	Jun 30, 2026	S	22,022	$30.07	D	4,374,870	I	Beneficially owned through Heritage Assets SCSp
Ordinary Shares^F2	Jul 1, 2026	S	32,422	$30.24	D	4,342,448	I	Beneficially owned through Heritage Assets SCSp

Table II — derivative securities

Security	Conv. / exercise price	Date	Code	Shares	A/D	Exercisable	Expires	Underlying	Underlying shares	Owned after	D/I
Business Combination Warrants (right to buy)^F4,F3	—	Jun 30, 2026	S	154	D	—	Sep 3, 2026	Ordinary Shares	154	14,987	I
Business Combination Warrants (right to buy)^F5,F3	—	Jul 1, 2026	S	41	D	—	Sep 3, 2026	Ordinary Shares	41	14,792	I

Explanation of responses

F1The price reported is a weighted average price. The Ordinary Shares were sold in multiple transactions at prices ranging from $30.00 to $30.29 per Ordinary Share, inclusive. The reporting person undertakes to provide to Arqit Quantum Inc. (the "Issuer") (ARQQ), any security holder of the Issuer or the staff of the Securities and Exchange Commission (the "Commission"), upon request, full information regarding the number of Ordinary Shares sold at each separate price within the range set forth in this footnote.
F2The price reported is a weighted average price. The Ordinary Shares were sold in multiple transactions at prices ranging from $30.00 to $30.93 per Ordinary Share, inclusive. The reporting person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the Commission, upon request, full information regarding the number of Ordinary Shares sold at each separate price within the range set forth in this footnote.
F3On September 19, 2024, the Issuer announced the implementation of a reverse stock split whereby every 25 outstanding ARQQ ordinary shares were consolidated into one ordinary share, par value $0.0025 per share. Each Business Combination Warrant has an exercise price of $11.50 and can be exercised at any time, at the holder's election, to purchase 0.04 of an ARQQ ordinary share on a post-reverse stock split basis, and cannot be exercised for fractional shares. Accordingly, on a post-reverse stock split basis holders of Business Combination Warrants are required to exercise at least 25 Business Combination Warrants in order to receive one whole ARQQ ordinary share at an aggregate exercise price of $287.50 per whole ARQQ ordinary share. The reporting person beneficially owns 369,792 Business Combination Warrants, which, if exercised in full, would be equivalent to 14,791.68 ARQQ ordinary shares on a post-reverse stock split basis.
F4The price reported is a weighted average price. The Business Combination Warrants were sold in multiple transactions at prices ranging from $1.22 to $1.79 per Business Combination Warrant, inclusive. The reporting person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the Commission, upon request, full information regarding the number of Business Combination Warrants sold at each separate price within the range set forth in this footnote.
F5The price reported is a weighted average price. The Business Combination Warrants were sold in multiple transactions at prices ranging from $1.35 to $1.79 per Business Combination Warrant, inclusive. The reporting person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the Commission, upon request, full information regarding the number of Business Combination Warrants sold at each separate price within the range set forth in this footnote.

Remarks

Due to the Issuer's status as a foreign private issuer pursuant to Rule 3a12-3(b) under the Securities Exchange Act of 1934 (the "Act"), the reporting person's transactions in the Issuer's securities are exempt from Sections 16(b) and 16(c) of the Act.