Arqit量子公司美股招股说明书(2025-09-15版)

We are offering pursuant to this prospectus supplement and the accompanying prospectus up to anaggregate of 48,561 of our ordinary shares, $0.0025 par value each (the “Ordinary Shares”) in satisfactionof payment to Deutsche Bank AG, London Branch for services rendered. Our Ordinary Shares are listed on The Nasdaq Capital Market under the symbol “ARQQ”. OnSeptember12, 2025, the last reported sales price of our Ordinary Shares was $33.71 per share. We are a “foreign private issuer,” and an “emerging growth company” each as defined under the federalsecurities laws, and, as such, we are subject to reduced public company reporting requirements. See thesection entitled “Summary — Implications of Being an Emerging Growth Company and a Foreign PrivateIssuer” for additional information. Investing in our Ordinary Shares involves risks. You should review carefully the risks and uncertaintiesdescribed under the heading “Risk Factors” beginning on pageS-4of this prospectus supplement and on page6of the accompanying prospectus, and under similar headings in any amendment or supplements to thisprospectus supplement or the accompanying prospectus. Neither the Securities and Exchange Commission nor any state securities commission has approved ordisapproved of these securities or passed upon the adequacy or accuracy of this prospectus supplement. Anyrepresentation to the contrary is a criminal offense. Delivery of the securities being offered pursuant to this prospectus supplement and the accompanyingprospectus is expected to be made on or about September16, 2025. TABLE OF CONTENTS Prospectus Supplement PageABOUT THIS PROSPECTUS SUPPLEMENTS-iiCAUTIONARY NOTE REGARDING FORWARD-LOOKING STATEMENTSS-iiiSUMMARYS-1RISK FACTORSS-4USE OF PROCEEDSS-5DIVIDEND POLICYS-6DESCRIPTION OF THE SECURITIES WE ARE OFFERINGS-7PLAN OF DISTRIBUTIONS-8LEGAL MATTERSS-9EXPERTSS-10WHERE YOU CAN FIND MORE INFORMATIONS-11DOCUMENTS INCORPORATED BY REFERENCES-12 Prospectus ABOUT THIS PROSPECTUS1INDUSTRY AND MARKET DATA2CAUTIONARY NOTE REGARDING FORWARD-LOOKING STATEMENTS3COMPANY OVERVIEW4CORPORATE INFORMATION4IMPLICATIONS OF BEING AN EMERGING GROWTH COMPANY AND A FOREIGN PRIVATEISSUER4RISK FACTORS6OFFER STATISTICS AND EXPECTED TIMETABLE7USE OF PROCEEDS7DESCRIPTION OF SECURITIES8DESCRIPTION OF EQUITY SECURITIES8DESCRIPTION OF DEBT SECURITIES9DESCRIPTION OF WARRANTS11PLAN OF DISTRIBUTION12ENFORCEMENT OF CIVIL LIABILITIES14EXPENSES17LEGAL MATTERS18EXPERTS18WHERE YOU CAN FIND MORE INFORMATION19 ABOUT THIS PROSPECTUS SUPPLEMENT This document is in two parts. The first part, the prospectus supplement, including the documentsincorporated by reference therein, describes the specific terms of this offering and certain matters relating tous. The second part, the accompanying prospectus, including the documents incorporated by referencetherein, provides more general information, some of which may not apply to this offering. Theaccompanying prospectus was filed as part of a registration statement on Form F-3 with the Securities andExchange Commission, or the SEC, on January29, 2025, as part of a “shelf” registration process. Under theshelf registration process, we may sell our Ordinary Shares in one or more offerings. Generally, when werefer to this prospectus supplement, we are referring to both parts of this document combined. We urge youto read carefully this prospectus supplement, the accompanying prospectus, the information incorporated byreference herein and therein, and any free writing prospectus that we authorize to be distributed to youbefore buying our Ordinary Shares being offered under this prospectus supplement. This prospectussupplement may supplement, update or change information contained in the accompanying prospectus. Tothe extent that any statement that we make in this prospectus supplement is inconsistent with statementsmade in the accompanying prospectus or any documents incorporated by reference therein, the statementsmade in this prospectus supplement will be deemed to modify or supersede those made in the accompanyingprospectus and such documents incorporated by reference therein. We have not authorized anyone to provide you with information that is different from that contained inor incorporated by reference into this prospectus supplement or the accompanying prospectus or in any freewriting prospectus we may authorize to be delivered or made available to you. We take no responsibility for,and can provide no assurance as to the reliability of, any other information that others may give you. Ifinformation in this prospectus supplement is inconsistent with the accompanying prospectus, you shouldrely on this prospectus supplement. We are not making an offer of these securities in any jurisdiction wherethe offer or sale is not permitted. You should not assume that the information provided by this prospectussupplement, the accompanying prospectus or the documents incorporated by reference herein or therein isaccurate as of any date o