Horizon Quantum Holdings HQ

Dr. Si-Hui Tan is our Chief Science Officer following the Business Combination and has been the Chief Science Officer of Horizon since March 2019. Dr. Tan is an accomplished academic and researcher in the field of quantum computing, with extensive experience in research and development. Prior to Horizon, from October 2013 to February 2019, Dr. Tan was a research Scientist at the Singapore University of Technology and Design, where she specialized in research and development as it pertains to quantum computation. Before her time at the Singapore University of Technology and Design, from December 2010 to October 2013, Dr. Tan was a research scientist at A*Star Data Storage Institute, where her research focused primarily on quantum optics and quantum communications. Dr. Tan has received ten academic honors and awards, most recently, as a 2025 SG Digital Leader and in 2021 she was named as a Singapore 100 Women in Tech. Dr. Tan's publications have also been cited over 1800 times. Dr. Tan obtained her Doctor of Philosophy in Physics from Massachusetts Institute of Technology, and her Bachelor of Science in Physics from the California Institute of Technology (Caltech).

Ms. Jill Turner serves as our director following the Business Combination. Currently, Ms. Turner serves as Chief Human Resources Officer for Broadcom Inc., a position she has held since April 2021. At Broadcom, Ms. Turner is the lead global Human Resources function and is responsible for all strategic human resources activity. Prior to Broadcom, between October 2013 and March 2021, Ms. Turner served as a human recourses senior vice president for Lumen Technologies, Inc., f/k/a Century Link, Inc., (Lumen). Prior to Lumen, between October 2013 and January 2000, Ms. Turner held various leadership positions within the human resources department at Honeywell International Inc. Ms. Turner received both her Master of Human Resources and Industrial Relations and her Bachelor of Science in Kinesiology from the University of Illinois at Urbana-Champaign. Ms. Turner was selected to serve on our Board due to her extensive experience in corporate leadership and human resources.

Mr. Harry L. You serves as our director following the Business Combination and previously served as the Chairman and a Director of DMY from March 3, 2022 to the date of the Merger, as well as the Chief Financial Officer of DMY from February 15, 2022 to the date of the Merger, and the Chief Executive Officer of DMY from February 26, 2025 to the date of the Merger. Mr. You is also currently the Executive Chairman of Berto Acquisition Corp. From March 3, 2022 until his resignation on March 15, 2023, Mr. You also served as the Co-Chief Executive Officer of DMY. Previously, Mr. You was the Chairman of the board of Coliseum Acquisition Corp. (Coliseum) from June 2023 to December 2024 and interim Chief Executive Officer and interim Chief Financial Officer of Coliseum from June 2023 to July 2023. He has served as the Executive Chairman and a director of Rain Enhancement Technologies Holdco Inc. since the company combined with Coliseum on December 31, 2024. He has also been a member of the audit committee of Broadcom Inc. (Broadcom) since January 2019 as well as Chairman of the Compensation Committee and a member of the Executive Committee of the board of directors of Broadcom. Previously, he was Chief Financial Officer from September 2016 to August 2019 and President in May 2019 and from September 2016 to February 2019 of GTY, a software as a service company that offers cloud-based solutions for the public sector. He was Executive Vice President in the Office of the Chairman of EMC Corporation (EMC) from 2008 to 2016. When Mr. You joined EMC in 2008, he oversaw corporate strategy and new business development, including mergers and acquisitions, joint ventures and venture capital activity. He was Chief Executive Officer from 2005 to 2007 and Interim Chief Financial Officer from 2005 to 2006 of BearingPoint Inc. He was Executive Vice President and Chief Financial Officer of Oracle Corporation (Oracle) from 2004 to 2005. Prior to joining Oracle, he held several key positions in finance, including as Chief Financial Officer of Accenture Ltd. and managing director in the Investment Banking Division of Morgan Stanley. He also served as a trustee of the U.S. Olympic Committee Foundation from 2016 to 2022. Mr. You served as a director and Chairman of the audit committee of IonQ, Inc. from October 2021 to February 2025. Mr. You served as Vice Chairman of the board of GTY from February 2019 to July 2022 and as director of Coupang, Inc. from January 2021 to June 2023, Genius Sports from April 2021 to December 2022, Rush Street from September 2019 to June 2022, dMY II (a special purpose acquisition company) from June 2020 to April 2021, dMY IV (a special purpose acquisition company) from December 2020 to April 2023, and Korn/Ferry International from 2005 to 2016. Mr. You holds an M.A. in Economics from Yale University and a B.A. in Economics from Harvard College. The Board has determined that Mr. You is well-qualified to serve on our Board due to his extensive and varied deal experience throughout his career, including his experience structuring Dell Technologies Inc.'s $67 billion acquisition of EMC as EMC's Executive Vice President, his experience as a member of IonQ's board of directors, his network of contacts in the technology sector, and his prior special purpose acquisition company experience with DMY and eight other special purpose acquisition companies (GTY, dMY I, dMY II, dMY III, dMY IV, dMY VI, Coliseum, and Berto).

Mr. Gregory Gould is our Chief Financial Officer following the Business Combination and has been the Chief Financial Officer of Horizon since August 2025. Mr. Gould is a seasoned professional with deep investment and operational expertise in the tech sector, from AI, to FinTech, InsurTech, blockchain, retail tech and PropTech. In addition to his role at Horizon, Mr. Gould acts as a strategic advisor to Penchant Holdings, Inc., and as a venture partner with 14 Peaks Capital Advisors LLC, positions he has held since December 2024 and May 2022, respectively. Mr. Gould's participation in 14 Peaks Capital is voluntary and advisory, and he receives no remuneration for any services he may choose to provide. 14 Peaks Capital does not participate in the quantum computing market, and Horizon does not consider Mr. Gould's involvement with them to be a conflict of interest with Horizon's interests or Mr. Gould's time. From December 2023 to May 2024, Mr. Gould was the Chief Financial Officer of FitMatch Inc., a leading AI-driven 'FitTech company that lets consumers find correct-fitting clothing. Prior to Fit, from May 2022 to September 2023, Mr. Gould was the Chief Financial Officer of Groundspeed Analytics, Inc., an InsurTech solution provider, where he rebuilt the finance team and successfully raised funding and helped drive a merger with Two Sigma Insurance Quantified, LP (a/ka/ Insurance Quantified). Earlier in his career, from January 2019 to January 2021, Mr. Gould was a Senior Vice President at Quarters Holdings GmbH, a PropTech company. From July 2017 to August 2019, was a Senior Advisor at CORESTATE Capital Holdings S.A. (XTERA: CCAP.DE), an investment manager and co-investor. Finally, Mr. Gould began his career at Goldman Sachs Group, Inc. (Goldman), where he became a Managing Director and Co-Deputy Director of Goldman's Global Technology Investment Research Group, leading equity and fixed income transactions. In 2023, Mr. Gould was identified as a Top 25 CFO of Miami by TheTopCFOs.com (f/k/a Finance & Investing), a publication focusing on business news and corporate actions related to banking, finance, and other topics relevant to public and private markets. Mr. Gould obtained his Bachelor of Science in Finance, Sloan School of Management from Massachusetts Institute of Technology, in 1990.

Ms. Danielle Lambert serves as our director following the Business Combination. Currently, Ms. Lambert serves as Chief Executive Officer and Founder of Penchant Holdings, Inc. (Penchant), a position she has held since December 2022. Prior to Penchant, between May 2010 and February 2014, Ms. Lambert was an initial investor and served as an advisor to Nest Labs, Inc. through their acquisition by Alphabet, Inc. Additionally, between October 2000 and November 2008, Ms. Lambert served in various capacities at Apple Inc. (Apple), ultimately achieving the title of Vice President of Human Resources. While at Apple, Ms. Lambert played a pivotal role in building the teams behind some of Apple's most iconic products. Ms. Lambert was selected to serve on our Board because of her extensive experience in early-stage business development and human resource expertise.

Dr. Joseph Fitzsimons is our Chairman and Chief Executive Officer following the Business Combination, and has been the Chief Executive Officer of Horizon since March 2019, after founding Horizon in January 2018. Dr. Fitzsimons is an academic authority on quantum computing with extensive research and development expertise. Prior to Horizon, from May 2013 to February 2019, Dr. Fitzsimons was a professor at the Singapore University of Technology and Design, achieving the position of a tenured associate professor in 2018. In addition, from November 2010 until February 2019, Dr. Fitzsimons held various position at the Center for Quantum Technologies in Singapore, ultimately becoming a Principal Investigator in 2017, a position Dr. Fitzsimons held for the remainder of his time there. Prior to that, between October 2007 and September 2010, Dr. Fitzsimons simultaneously held positions as a Senior Research Fellow and a Junior Research Fellow within Oxford University's Department of Materials and Merton College, respectively. Additionally, from 2006 until 2007, Dr. Fitzsimons was a Graduate Teaching Assistant at Oriel College. Dr. Fitzsimons has held multiple visiting positions at academic institutions between 2006 and 2018, included at the University of California, Berkley, University College in Dublin, Ireland and the Institute for Quantum Computing at the University of Waterloo. Dr. Fitzsimons has received several awards and distinctions, most notably from the MIT Technology Review, the Singapore National Research Foundation and the University of Oxford. Since 2008, Dr. Fitzsimons has been awarded ten research grants from a variety of governmental and academic institutions. Dr. Fitzsimons received his doctorate in 2007 from the University of Oxford's Department of Materials, having completed a doctoral thesis titled Architectures for Quantum Computation under Restricted Controls. Prior to this, he was awarded his Bachelor of Science in theoretical physics from University College Dublin, Ireland, achieving first class honors. Dr. Fitzsimons' work has been cited over 6,900 times, he is listed as an inventor on three patents related to quantum computing, has authored in excess of 60 publications and is a member of multiple professional societies, including as president of the Southeast Asia Quantum Industry Association and as board member of the Irish Chamber of Commerce in Singapore

Catherine Fitzsimons will serve as the Chief Legal and Compliance Officer, EVP of Strategic Initiatives and Company Secretary of the Company beginning on May 11, 2026, and will be responsible for overseeing all the legal, regulatory, compliance and corporate governance matters relating to the Company. Since February 2015, Ms. Fitzsimons has served in various roles at Fidelity International Ltd. (Fidelity), ultimately achieving the title Director of Strategic Initiatives. Over the course of her time with Fidelity, Ms. Fitzsimons served as Head of Global Product Legal and provided legal support and advice in relation to Fidelity's European and Cross-Border fund ranges. Additionally, Ms. Fitzsimons has served as a non-executive director on Fidelity's Irish fund ranges. Prior to joining Fidelity, between May 2009 and January 2015, Ms. Fitzsimons practiced financial services law with a specific focus on asset management and investment funds, advising a wide range of domestic and international clients on all aspects of their business, including their asset management activities, and the structuring, establishment, marketing and sale of investment vehicles in Ireland and other jurisdictions. Ms. Fitzsimons is a member of the Law Society of Ireland, and has also acted as a lecturer and internal examiner. Ms. Fitzsimons is a certified investment fund director and holds a Bachelor of Civil Law and a Post-Graduate Diploma in International Financial Services Law from University College Dublin, as well as a Diploma in Applied Finance Law.