{"transactions":[{"id":4618857,"issuer":{"id":5127,"kind":"organization","name":"Horizon Quantum Holdings Ltd.","symbol":"HQ"},"owners":[{"id":56179,"kind":"person","name":"Fitzsimons Joseph Francis","position":1,"cik":"0002122720","reported_name":"Fitzsimons Joseph Francis","relationship":{"director":true,"officer":true,"ten_percent_owner":true,"other":false,"officer_title":"Chief Executive Officer"}}],"security":"Restricted Stock Unit","published_at":"2026-09-16T01:30:10.000Z","date":"2026-09-12","kind":"exercise","planned":false,"acquired":true,"shares":14321,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"derivative.exercise_price","element":"conversionOrExercisePrice","label":"F2","text":"On June 12, 2026 (the \"Grant Date\"), Dr. Fitzsimons was granted a total of 229,148 unvested restricted stock units (\"RSUs\"), each representing a contingent right to receive one Class A ordinary share, with no par value (\"Class A Ordinary Share\"), of Horizon Quantum Holdings Ltd. (the \"Company\") upon vesting, for no consideration. The RSUs granted to Dr. Fitzsimons vest in sixteen approximately equal installments on successive quarterly anniversaries of the Grant Date and are subject to Dr. Fitzsimons's continued employment with the Company through each applicable vesting date."},{"field":"shares","element":"transactionShares","label":"F1","text":"On September 12, 2026, 14,321 of Dr. Fitzsimons's RSU's vested."},{"field":"derivative.exercise_date","element":"exerciseDate","label":"F1","text":"On September 12, 2026, 14,321 of Dr. Fitzsimons's RSU's vested."},{"field":"derivative.exercise_date","element":"exerciseDate","label":"F2","text":"On June 12, 2026 (the \"Grant Date\"), Dr. Fitzsimons was granted a total of 229,148 unvested restricted stock units (\"RSUs\"), each representing a contingent right to receive one Class A ordinary share, with no par value (\"Class A Ordinary Share\"), of Horizon Quantum Holdings Ltd. (the \"Company\") upon vesting, for no consideration. The RSUs granted to Dr. Fitzsimons vest in sixteen approximately equal installments on successive quarterly anniversaries of the Grant Date and are subject to Dr. Fitzsimons's continued employment with the Company through each applicable vesting date."},{"field":"derivative.expiration_date","element":"expirationDate","label":"F2","text":"On June 12, 2026 (the \"Grant Date\"), Dr. Fitzsimons was granted a total of 229,148 unvested restricted stock units (\"RSUs\"), each representing a contingent right to receive one Class A ordinary share, with no par value (\"Class A Ordinary Share\"), of Horizon Quantum Holdings Ltd. (the \"Company\") upon vesting, for no consideration. The RSUs granted to Dr. Fitzsimons vest in sixteen approximately equal installments on successive quarterly anniversaries of the Grant Date and are subject to Dr. Fitzsimons's continued employment with the Company through each applicable vesting date."}],"balance_after":214827,"derivative":{"exercise_price":0,"underlying":"Class A Ordinary Shares","underlying_shares":14321},"source":{"system":"sec-edgar","filing":"0001213900-26-100279","document":"ownership.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":4,"url":"https://www.sec.gov/Archives/edgar/data/2122720/000121390026100279/ownership.xml","form_type":"4"}},{"id":4618856,"issuer":{"id":5127,"kind":"organization","name":"Horizon Quantum Holdings Ltd.","symbol":"HQ"},"owners":[{"id":56179,"kind":"person","name":"Fitzsimons Joseph Francis","position":1,"cik":"0002122720","reported_name":"Fitzsimons Joseph Francis","relationship":{"director":true,"officer":true,"ten_percent_owner":true,"other":false,"officer_title":"Chief Executive Officer"}}],"security":"Restricted Stock Unit","published_at":"2026-09-16T01:30:10.000Z","date":"2026-06-12","kind":"grant","planned":false,"acquired":true,"shares":229148,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"derivative.exercise_price","element":"conversionOrExercisePrice","label":"F2","text":"On June 12, 2026 (the \"Grant Date\"), Dr. Fitzsimons was granted a total of 229,148 unvested restricted stock units (\"RSUs\"), each representing a contingent right to receive one Class A ordinary share, with no par value (\"Class A Ordinary Share\"), of Horizon Quantum Holdings Ltd. (the \"Company\") upon vesting, for no consideration. The RSUs granted to Dr. Fitzsimons vest in sixteen approximately equal installments on successive quarterly anniversaries of the Grant Date and are subject to Dr. Fitzsimons's continued employment with the Company through each applicable vesting date."},{"field":"shares","element":"transactionShares","label":"F2","text":"On June 12, 2026 (the \"Grant Date\"), Dr. Fitzsimons was granted a total of 229,148 unvested restricted stock units (\"RSUs\"), each representing a contingent right to receive one Class A ordinary share, with no par value (\"Class A Ordinary Share\"), of Horizon Quantum Holdings Ltd. (the \"Company\") upon vesting, for no consideration. The RSUs granted to Dr. Fitzsimons vest in sixteen approximately equal installments on successive quarterly anniversaries of the Grant Date and are subject to Dr. Fitzsimons's continued employment with the Company through each applicable vesting date."},{"field":"derivative.exercise_date","element":"exerciseDate","label":"F2","text":"On June 12, 2026 (the \"Grant Date\"), Dr. Fitzsimons was granted a total of 229,148 unvested restricted stock units (\"RSUs\"), each representing a contingent right to receive one Class A ordinary share, with no par value (\"Class A Ordinary Share\"), of Horizon Quantum Holdings Ltd. (the \"Company\") upon vesting, for no consideration. The RSUs granted to Dr. Fitzsimons vest in sixteen approximately equal installments on successive quarterly anniversaries of the Grant Date and are subject to Dr. Fitzsimons's continued employment with the Company through each applicable vesting date."},{"field":"derivative.expiration_date","element":"expirationDate","label":"F2","text":"On June 12, 2026 (the \"Grant Date\"), Dr. Fitzsimons was granted a total of 229,148 unvested restricted stock units (\"RSUs\"), each representing a contingent right to receive one Class A ordinary share, with no par value (\"Class A Ordinary Share\"), of Horizon Quantum Holdings Ltd. (the \"Company\") upon vesting, for no consideration. The RSUs granted to Dr. Fitzsimons vest in sixteen approximately equal installments on successive quarterly anniversaries of the Grant Date and are subject to Dr. Fitzsimons's continued employment with the Company through each applicable vesting date."},{"field":"derivative.underlying_shares","element":"underlyingSecurityShares","label":"F2","text":"On June 12, 2026 (the \"Grant Date\"), Dr. Fitzsimons was granted a total of 229,148 unvested restricted stock units (\"RSUs\"), each representing a contingent right to receive one Class A ordinary share, with no par value (\"Class A Ordinary Share\"), of Horizon Quantum Holdings Ltd. (the \"Company\") upon vesting, for no consideration. The RSUs granted to Dr. Fitzsimons vest in sixteen approximately equal installments on successive quarterly anniversaries of the Grant Date and are subject to Dr. Fitzsimons's continued employment with the Company through each applicable vesting date."}],"balance_after":229148,"derivative":{"exercise_price":0,"underlying":"Class A Ordinary Shares","underlying_shares":229148},"source":{"system":"sec-edgar","filing":"0001213900-26-100279","document":"ownership.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":3,"url":"https://www.sec.gov/Archives/edgar/data/2122720/000121390026100279/ownership.xml","form_type":"4"}},{"id":4618855,"issuer":{"id":5127,"kind":"organization","name":"Horizon Quantum Holdings Ltd.","symbol":"HQ"},"owners":[{"id":56179,"kind":"person","name":"Fitzsimons Joseph Francis","position":1,"cik":"0002122720","reported_name":"Fitzsimons Joseph Francis","relationship":{"director":true,"officer":true,"ten_percent_owner":true,"other":false,"officer_title":"Chief Executive Officer"}}],"security":"Class A Ordinary Shares","published_at":"2026-09-16T01:30:10.000Z","date":"2026-09-12","kind":"disposition_to_issuer","planned":false,"acquired":false,"shares":3438,"price":15.22,"value":52326.36,"ownership":{"direct":true},"footnotes":[{"field":"date","element":"transactionDate","label":"F1","text":"On September 12, 2026, 14,321 of Dr. Fitzsimons's RSU's vested."},{"field":"shares","element":"transactionShares","label":"F3","text":"The reported disposition to the Company reflects the settlement in cash of a portion of the RSUs which vested on September 12, 2026, at a price per ordinary share of $15.22, the last reported sales price of the Company's Class A Ordinary Shares on September 11, 2026."},{"field":"price","element":"transactionPricePerShare","label":"F3","text":"The reported disposition to the Company reflects the settlement in cash of a portion of the RSUs which vested on September 12, 2026, at a price per ordinary share of $15.22, the last reported sales price of the Company's Class A Ordinary Shares on September 11, 2026."}],"balance_after":10883,"source":{"system":"sec-edgar","filing":"0001213900-26-100279","document":"ownership.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":2,"url":"https://www.sec.gov/Archives/edgar/data/2122720/000121390026100279/ownership.xml","form_type":"4"}},{"id":4618854,"issuer":{"id":5127,"kind":"organization","name":"Horizon Quantum Holdings Ltd.","symbol":"HQ"},"owners":[{"id":56179,"kind":"person","name":"Fitzsimons Joseph Francis","position":1,"cik":"0002122720","reported_name":"Fitzsimons Joseph Francis","relationship":{"director":true,"officer":true,"ten_percent_owner":true,"other":false,"officer_title":"Chief Executive Officer"}}],"security":"Class A Ordinary Shares","published_at":"2026-09-16T01:30:10.000Z","date":"2026-09-12","kind":"exercise","planned":false,"acquired":true,"shares":14321,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"date","element":"transactionDate","label":"F1","text":"On September 12, 2026, 14,321 of Dr. Fitzsimons's RSU's vested."},{"field":"shares","element":"transactionShares","label":"F1","text":"On September 12, 2026, 14,321 of Dr. Fitzsimons's RSU's vested."},{"field":"price","element":"transactionPricePerShare","label":"F2","text":"On June 12, 2026 (the \"Grant Date\"), Dr. Fitzsimons was granted a total of 229,148 unvested restricted stock units (\"RSUs\"), each representing a contingent right to receive one Class A ordinary share, with no par value (\"Class A Ordinary Share\"), of Horizon Quantum Holdings Ltd. (the \"Company\") upon vesting, for no consideration. The RSUs granted to Dr. Fitzsimons vest in sixteen approximately equal installments on successive quarterly anniversaries of the Grant Date and are subject to Dr. Fitzsimons's continued employment with the Company through each applicable vesting date."}],"balance_after":14321,"source":{"system":"sec-edgar","filing":"0001213900-26-100279","document":"ownership.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/2122720/000121390026100279/ownership.xml","form_type":"4"}},{"id":828898,"issuer":{"id":5127,"kind":"organization","name":"Horizon Quantum Holdings Ltd.","symbol":"HQ"},"owners":[{"id":56179,"kind":"person","name":"Fitzsimons Joseph Francis","position":1,"cik":"0002122720","reported_name":"Fitzsimons Joseph Francis","relationship":{"director":true,"officer":true,"ten_percent_owner":true,"other":false,"officer_title":"Chief Executive Officer"}}],"security":"Class B Ordinary Shares","published_at":"2026-03-24T22:30:09.000Z","date":"2026-03-19","kind":"grant","planned":false,"acquired":true,"shares":19744585,"ownership":{"direct":true},"footnotes":[{"field":"security","element":"securityTitle","label":"F1","text":"Each Class B ordinary share, with no par value (the \"Class B Ordinary Shares\"), is convertible, at any time, in exchange for one Class A ordinary share, with no par value (the \"Class A Ordinary Shares\")."},{"field":"date","element":"transactionDate","label":"F2","text":"Class B Ordinary Shares, received on March 19, 2026, upon the closing of business combination (the \"Business Combination\") contemplated by the Business Combination Agreement, dated as of September 9, 2025 (the \"BCA\"), by and among Horizon Quantum Computing Pte. Ltd. (\"Legacy Horizon\"), dMY Squared Technology Group, Inc., Horizon Quantum Holdings Ltd. (the \"Company\") and certain other parties, as described in the Registration Statement on Form F-4, as amended and supplemented (File No. 333-292737), initially filed with the U.S. Securities and Exchange Commission on January 14, 2026, and declared effective on February 17, 2026."},{"field":"price","element":"transactionPricePerShare","label":"F3","text":"Pursuant to the BCA and as a result of the Business Combination, Dr. Fitzsimons exchanged his then outstanding 8,108,696 ordinary shares of Legacy Horizon for 19,744,585 Class B Ordinary Shares of the Company."}],"balance_after":19744585,"source":{"system":"sec-edgar","filing":"0001213900-26-033688","document":"ownership.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/2088256/000121390026033688/ownership.xml","form_type":"4"}}]}