Join SIX at Sibos 2025

CEO SIX

Bjørn Sibbern has been the CEO of SIX since January 2025. Previously, since joining SIX in January 2024, he led the stock exchange business as Global Head Exchanges and a Member of the Executive Board. Bjørn Sibbern has experience managing large teams in the fields of trading, funds, post-trade, listings, IPOs, data, index business, and technology. Before joining SIX, he served as Executive Vice President and President of European Markets at Nasdaq. In this role, he led the Nasdaq markets and exchanges across the Nordic and Baltic regions. He was also responsible for trading, listing, clearing, settlement, and the data business in Sweden, Denmark, Finland, Iceland, and the Baltic nations. Prior to this, Bjørn was Executive Vice President and responsible for Nasdaq global data, data & analytics and index business working out of Nasdaq headquarter in New York. Before joining Nasdaq, Bjørn Sibbern was CEO at E*TRADE Bank Denmark from 2006 to 2008 and held key roles at OMX and Stocknet Norway. The Danish citizen holds an Executive Master in Business Administration, a Graduate Diploma in Finance, and a Master in Business Administration and Commercial Law from Copenhagen Business School.

Other Activities and Mandates

• Chairman, Bolsas y Mercados Españoles SA (BME), Madrid
• Chairman or Board Member of various SIX Group Ltd companies
• Chairman Working Committee, World Federation of Exchanges WFE, London

Head Securities Services

Rafael Moral Santiago has been Head Securities Services and a member of the Executive Board of SIX since June 2025. Before joining SIX, he held different leadership positions at HSBC in Hong Kong and London from 2015 until 2024. In his most recent role, he served as Global Head of Country Management Securities Services for HSBC, leading the regional strategy and coordination of the bank’s securities services business across more than thirty markets.

Prior positions included Head of Securities Services for Europe, as well as for Asia Pacific & MENA. From 2002 until 2015 Rafael Moral Santiago worked at Deutsche Bank in various management roles in Germany, the USA and Singapore, most recently as Global Head of Investor Services responsible for Custody, Clearing, Fund Services, and Securities Lending.

Before joining Deutsche Bank, he gained business leadership experience as the CFO and executive board member at 100world (now Senacor Technologies), following a position as strategy consultant at McKinsey & Co. A Spanish citizen, Rafael Moral Santiago graduated from the HHL Leipzig Graduate School of Management and attended INSEAD’s MBA and International Executive Programmes.

Head Commercials Securities Services

Marcus Harréus leads the Commercials organisation within Securities Services. In this capacity, he leads all of the relationship management, product management and sales activities for the post-trade area. He also heads the legal entity SIX SIS AG which provides settlement and custody services.

He joined SIX 2013 and prior to SIX, Marcus had a long and varied career in the financial sector. 

Head Financial Information

Marion Leslie joined SIX Group in January 2020 as Head Financial Information and a member of the SIX Executive Board. As Head Financial Information, Marion Leslie leads the SIX global data business, serving financial institutions worldwide with critical data and insights to support their clients. She is also the representative on the Executive Board for Sustainability.

Leading global businesses and operations at scale, with a strong emphasis on data and technology, are the hallmarks of her career in financial services. Prior to joining SIX, Marion Leslie was Managing Director, Enterprise at Refinitiv (London Stock Exchange) with responsibility for delivering market data, platforms and services to the global financial markets. Before that, she held a variety of executive roles within London Stock Exchange Group, having joined Reuters in 1994. Marion Leslie holds a Post Graduate Certificate in Education in French and German from the University of Cambridge. She was named one of the 100 Most Influential Women in European Finance by Financial News every year from 2020-2024, was listed as one of Swiss Finance’s Women to Watch in 2022, and was included in the World Federation of Exchanges Women Leaders List 2021. 

Other Activities and Mandates

• President or Board Member of various SIX Group Ltd companies
• Board Member, Bolsas y Mercados Españoles SA (BME), Madrid
• Board Member, Swiss Sustainable Finance, Zurich
• Board Member, Advance, Zurich
• Chair, UK Hydrographic Office, Taunton

Head Banking Services

Dieter Goerdten has headed the Banking Services business unit since December 2022. He previously had been in charge of the Banking Services business unit’s Products & Solutions department since September 2018. He earned a degree in economics from the University of Hamburg, holds a Master of Advanced Studies degree in corporate finance from the University of Applied Sciences and Arts of Northwestern Switzerland, and has many years of international managerial experience in the Swiss financial sector. His professional background also includes career experience in the airline industry (at Deutsche Lufthansa in Frankfurt, Cologne, and Hamburg) and in the field of international development cooperation (at the German Development Cooperation Agency), with multiyear stints in Costa Rica and Ethiopia. In Switzerland he has held various management roles at UBS, PostFinance, the St. Gallen-based Bankenberatungszentrum, and the consultancy firm Boxcon. Dieter Goerdten served also as the interim Chief Executive Officer of Swiss Euro Clearing Bank in Frankfurt.

Other Activities and Mandates

• Chairman or Board Member of various SIX Group Ltd companies
• Chairman, Terravis Ltd, Zurich
• Chairman, SECB GmbH, Frankfurt

Head Ecosystem Debit & ATM Services

Christoph Müller joined SIX in 2019 and will assume the role of Head Banking Services and member of the Executive Board as of October 1, 2025. He brings over 30 years of experience in banking and payments, having held leadership roles at Credit Suisse and UBS, and co-founding a fintech startup. At SIX, he most recently served as Deputy Head Banking Services and Head Ecosystem Debit & ATM Services. Christoph holds an Executive MBA in Management of Technology from the École Polytechnique Fédérale de Lausanne and the University of Lausanne, as well as a bachelor's degree in business administration from the Zurich University of Applied Sciences.

Head Strategy & Architecture

Dr. Cornelius Dorn is Head of Strategy & Architecture for Banking Services at SIX, a role he has held since joining the company in 2018. He brings extensive experience in financial services and technology, having previously served as Head of Global Business Architecture at UBS Wealth Management. Cornelius holds a doctorate and graduated from the Karlsruhe Institute of Technology. At SIX, he plays a key role in shaping the strategic and technological direction of banking services, including initiatives like the Secure Swiss Finance Network (SSFN), which enhances secure data exchange across the Swiss financial sector.

Head SDX

David Newns, a finance professional with over 25 years of experience, joined SIX as Head of SDX in 2021. With a deep knowledge of DLT applications in financial services, David advocates for wholesale CBDC as a foundational component for the successful deployment and leveraging of the full potential of DLT and blockchain technology within the global capital markets. Having an extensive background in traditional finance, he understands the importance of investor protection, robust control environments, a clear governance framework, and adherence to regulatory obligations when applied to the digital asset space. David led SDX to achieve significant milestones, including issuing the first digital bond and tokenizing equity shares. In 2023, SDX made history by settling securities transactions in wholesale CBDC.

Head Digital Assets

Marco Kessler joined SDX in October 2018 and has been a key member of the team since its beginning. Marco brings 14 years of experience in capital markets and digital transformation to SDX. During his time at Accenture, Marco contributed significantly to large-scale digital transformation programs for global Swiss banks, particularly in wealth management, advisory and core banking segment. His expertise lies at the forefront of innovation, driving the adoption of digital assets in capital markets and financial market infrastructures.
Throughout his career, Marco has specialized in management and technology consulting, with a focus on business architecture for financial services and IT technology strategy. His contributions to SDX have been invaluable, as he continues to play a pivotal role in building the platform from the ground up. Marco’s dedication to driving innovation and his deep understanding of financial markets make him an integral part of the SDX team.