Xanadu Quantum Technologies Ltd-B美股招股说明书(2026-08-21版)

SUPPLEMENT NO. 3 TO PROSPECTUS OF XANADU QUANTUM TECHNOLOGIES LIMITED This prospectus supplement amends and supplements the prospectus dated May 1, 2026, as supplemented or amended from time totime (the “Prospectus”), which forms a part of our Registration Statement on Form F-1 (Registration Statement No. 333-295256). Thisprospectus supplement is being filed to update and supplement the information included or incorporated by reference in the Prospectuswith the information contained in our Report on Form 6-K, which was furnished to the Securities and Exchange Commission onAugust 5, 2026 (the “Form 6-K”). Accordingly, we have attached the Form 6-K to this prospectus supplement. This prospectus supplement updates and supplements the information in the Prospectus and is not complete without and may not bedelivered or utilized except in combination with, the Prospectus, including any amendments or supplements thereto. This prospectussupplement should be read in conjunction with the Prospectus and if there is any inconsistency between the information in theProspectus and this prospectus supplement, you should rely on the information in this prospectus supplement. Our Class B Subordinate Voting Shares are listed on the Nasdaq Global Market (“Nasdaq”) under the symbol “XNDU” and theToronto Stock Exchange (the “TSX”) under the symbol “XNDU.” On August 20, 2026, the last reported sales prices of the Class BSubordinate Voting Shares on Nasdaq and the TSX were $10.11 and C$13.97, respectively. Investing in our securities involves a high degree of risk. You should review carefully the risks and uncertainties describedunder the heading “Risk Factors” beginning on page 1 of the Annual Report and beginning on page 6 of the Prospectus, andunder similar headings in any amendments or supplements to the Prospectus. None of the Securities and Exchange Commission, any state securities commission or the securities commission or regulatoryauthority of any Canadian province or territory has approved or disapproved of the securities offered by this prospectussupplement or the Prospectus or determined if the Prospectus or this prospectus supplement is accurate or adequate. Anyrepresentation to the contrary is a criminal offense. This Supplement No. 3 is dated August 21, 2026. UNITED STATESSECURITIES AND EXCHANGE COMMISSIONWashington, D.C. 20549 FORM6-K Report of Foreign Private IssuerPursuant to Rule 13A-16 or 15D-16of the Securities Exchange Act of 1934 For the month of August 2026 Commission File Number: 001-43205 Xanadu Quantum Technologies Limited(Translation of registrant’s name into English) 777 Bay Street, Toronto, Ontario M5G 2C8(Address of principal executive offices) Indicate by check mark whether the registrant files or will file annual reports under cover of Form 20-F or Form 40-F. Form 20-F☒Form 40-F☐ Signature Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on itsbehalf by the undersigned hereunto duly authorized. Dated: August5, 2026 Exhibit Index Xanadu Announces Second Quarter 2026Results The Company is on a Mission to Build Quantum Computers That Are Useful and Available toPeople Everywhere TORONTO | August 5, 2026 /GLOBE NEWSWIRE/ -- Xanadu Quantum Technologies Limited (“Xanadu” or the “Company”)(NASDAQ: XNDU) (TSX: XNDU), a leading photonic quantum computing company, today announced financial results for thesecond quarter ended June30, 2026. “Every decision at Xanadu comes back to one mission: building quantum computers that are useful and available to peopleeverywhere,” said Dr. Christian Weedbrook, Founder and Chief Executive Officer of Xanadu. “This quarter, we made real progress onthat mission. We set new performance records across some of our core photonic components, and we’re pairing that hardware progresswith software breakthroughs that we believe make quantum algorithms more efficient today.” “We ended the quarter in a strong financial position, with $312.8 million of cash on hand,” said Michael Trzupek, Chief FinancialOfficer of Xanadu. “That balance sheet gives us the runway to keep investing in the engineering talent and wafer capacity our roadmaprequires. During the quarter we raised $67.2million under our synthetic at-the-market facility with Yorkville Advisors, and we intendto remain disciplined, drawing on that facility only when we believe conditions are favorable to the Company, including itsshareholders.” Second Quarter Business Milestones and Announcements ●Chip packaging and fabrication:Achieved an average edge-coupling loss of 0.085 dB per facet, supported by theCompany’s internal packaging facility and collaborations with Corning and DISCO, and increased foundry fabrication runsacrossits two core material platforms:thin-film lithium niobate(up approximately 75%)and silicon nitride(upapproximately 50%). ●U.S. operations expansion:Announced a significant expansion of U.S. operations anchor