SIX Digital Exchange Market Activity Tracker: SDX Performance and Development 2025

SIX Digital Exchange (SDX) holds a unique position in global financial market infrastructure: it is the world’s first fully regulated distributed ledger technology exchange and central securities depository, operating under an explicit FINMA DLT trading facility licence granted in 2021. Built as a subsidiary of SIX Group — the operator of the Swiss Exchange (SIX Swiss Exchange) and Swiss CSD (SIX SIS) — SDX represents Switzerland’s institutional commitment to building next-generation financial market infrastructure on DLT foundations. This tracker monitors SDX’s operational activity, issuance milestones, central bank money integration, and strategic development.

SDX Overview: The World’s First Regulated DLT Exchange

SDX was conceived in 2018 and launched commercially in 2021 following a development period that required building not only technology infrastructure but also the regulatory framework to licence it. Key structural facts:

• Parent: SIX Group, the Swiss financial market infrastructure group that also operates SIX Swiss Exchange and SIX SIS (the Swiss central securities depository for traditional securities)
• Regulatory status: FINMA-licenced DLT trading facility (DLT-Handelssystem) — a licence category created specifically by the Swiss DLT Act of 2021
• Function: both a central securities depository (SDX CSD) for creating and holding tokenised securities, and an exchange (SDX Exchange) for secondary market trading of those securities
• Geographic scope: Switzerland, with ongoing initiative to attract international issuers and participants
• Settlement: integrates with SIX SIS for traditional securities; Project Helvetia demonstrates SNB wholesale CBDC settlement for tokenised securities on SDX
• Investment: SIX Group’s cumulative investment in SDX is estimated at CHF 400–600 million, representing one of the largest single institutional investments in DLT financial market infrastructure globally

The issuance of a FINMA DLT trading facility licence to SDX in 2021 was globally unprecedented. Unlike regulatory sandboxes or limited-scope pilot regimes (such as the EU’s DLT Pilot Regime introduced in 2023), SDX operates under a permanent, full regulatory licence with no sunset clause or issuance cap — making it a genuinely operational venue rather than an experiment.

SDX Issuance and Activity Timeline

The following table tracks SDX’s operational milestones and issuance activity from its pilot phase through 2025:

Note: Volume figures represent estimated cumulative primary issuance value. Secondary market volumes remain immaterial relative to primary issuances.

SDX Technical Architecture

SDX’s technical infrastructure is built on a permissioned distributed ledger network, specifically utilising a variant of R3’s Corda protocol adapted for the requirements of a regulated central securities depository. Key architectural elements:

Permissioned network model: unlike public blockchains such as Ethereum, SDX operates a closed network where participants must be approved, onboarded via legal agreements, and technically integrated before they can access the platform. This permissioned model aligns with FINMA’s regulatory requirements for a licenced financial market infrastructure and with the operational requirements of institutional participants who cannot expose their activities to public network validators.

Integration with SIX Group infrastructure: SDX is not a standalone island — it integrates with SIX SIS (the traditional CSD), SIX Swiss Exchange, and SIX’s existing payment and messaging infrastructure. This integration enables a bridge between traditional and tokenised securities, allowing issuers who operate across both worlds to manage positions coherently. The SIS–SDX bridge is technically significant: it allows a bond to exist simultaneously in traditional and tokenised form (dual-register) during transition periods.

CSD layer: the SDX CSD provides the legal and operational custody function for tokenised securities. When a bank or issuer creates a Registerwertrecht on SDX, the SDX CSD is the registry of record for that instrument. The CSD manages corporate actions, coupon payments, and redemptions digitally.

Exchange layer: the SDX Exchange sits above the CSD, providing order matching, price discovery, and trade execution for secondary market transactions in tokenised securities. Settlement of trades is atomic (delivery versus payment) within the SDX system.

Project Helvetia: SNB CBDC Integration with SDX

The most strategically significant development in SDX’s history beyond its initial launch is Project Helvetia, the Swiss National Bank’s wholesale central bank digital currency (CBDC) experiment conducted in partnership with SDX, BIS Innovation Hub, and participating commercial banks.

Project Helvetia has proceeded through three phases:

Phase I (2020): proof-of-concept demonstrating that SNB wholesale CBDC could be issued on a distributed ledger and used to settle tokenised asset transactions. BIS Innovation Hub and SIX Group collaboration.

Phase II (2021–2022): extended to integrate Project Helvetia CBDC settlement with existing RTGS (real-time gross settlement) infrastructure, demonstrating interoperability between traditional payment systems and DLT settlement.

Phase III (2023): live issuance of tokenised bonds by commercial banks on SDX, settled using real wholesale Swiss franc CBDC issued by the SNB. This is the critical milestone: actual central bank money — not a simulation, not commercial bank money — was used to settle real securities transactions on SDX. Participating banks included UBS, Zürcher Kantonalbank, Basler Kantonalbank, Commerzbank, Goldman Sachs, and Hypothekarbank Lenzburg among others.

Project Helvetia Phase III is globally significant because it resolves the settlement risk question that has haunted digital securities: if tokenised bonds are settled with commercial bank money (a private liability), there is credit risk in settlement. Central bank money settlement eliminates this risk, putting tokenised securities on the same settlement basis as traditional securities settled through central bank payment systems. No other jurisdiction has achieved live CBDC settlement of tokenised securities at comparable scale.

SDX Participant Count and Connectivity

SDX’s CSD participant roster has grown from the initial 5–10 launch participants to approximately 20–25 institutions as of 2025. Participants include:

• Swiss universal banks: UBS, ZKB (Zürcher Kantonalbank), Basler Kantonalbank, and other cantonal banks
• International banks: Commerzbank, Goldman Sachs, and several Asian institutions seeking Swiss DLT capabilities
• Custodian banks: institutions providing custody services to end investors who hold SDX-settled securities
• Broker-dealers: institutions connecting to SDX for secondary market trading capabilities

Each new participant requires legal agreement execution, technical integration (typically 3–6 months), and FINMA notification. The onboarding process is resource-intensive, which partly explains why participant growth has been methodical rather than rapid.

The Liquidity Challenge: Primary Success, Secondary Thin

SDX’s core operational challenge entering 2025 is the gap between primary market success and secondary market depth. Primary issuances — the origination and initial settlement of tokenised bonds — have proceeded reliably and have attracted genuinely large transactions (UBS CHF 375m). The secondary market — where investors trade previously issued tokenised securities — remains extremely thin.

This is not unique to SDX: virtually every regulated tokenised securities venue globally faces the same problem. The structural constraints are:

Participant mandate mismatch: institutional investors in tokenised bonds — pension funds, insurers, bank treasury desks — typically operate hold-to-maturity mandates. They purchase at issuance and hold until redemption. They are not natural secondary market participants.

Benchmark absence: there is no established SDX secondary market yield curve against which to price tokenised securities. Without benchmark pricing, secondary trading requires bilateral negotiation, which is expensive and operationally cumbersome.

Portfolio management system integration: for secondary trading to be efficient at scale, portfolio managers’ order management systems (Bloomberg AIM, BlackRock Aladdin, etc.) need to natively interface with SDX’s secondary market. This integration does not currently exist in standard form.

SDX’s secondary market development strategy focuses on increasing participant count, facilitating more varied issuances (to create a natural universe of securities for portfolio diversification), and working with technology vendors to build SDX connectivity into portfolio management infrastructure.

SDX International Expansion Strategy

SIX Group has articulated an international expansion strategy for SDX that targets two key objectives: attracting non-Swiss issuers to issue on SDX’s infrastructure, and connecting SDX with international tokenised securities venues to enable cross-border settlement.

On issuers: SDX has engaged with international supranational institutions and sovereign issuers seeking to issue in Swiss francs or to access Swiss institutional investor demand. The World Bank pilot of 2018 demonstrated the concept; converting this into a recurring international issuer programme is SDX’s primary commercial development in the issuance segment.

On connectivity: discussions around interoperability between SDX and other regulated DLT venues (including Singapore’s SGX digital asset platform and Luxembourg’s tokenised securities infrastructure) are at an early stage but conceptually aligned with BIS Innovation Hub’s work on cross-border CBDC and securities settlement.

Outlook: When Does SDX Reach Meaningful Secondary Market Volume?

The question most institutional stakeholders ask about SDX is when — not whether — secondary market volumes will become material. The conditions required are:

1. 30+ CSD participants: a minimum viable liquidity pool requires substantially more institutions than the current 20–25
2. CHF 5+ billion in tokenised securities outstanding on SDX: a diverse enough universe of tokenised instruments to support portfolio construction and active trading
3. Buy-side integration: at least 5–10 significant Swiss pension funds or insurers with active mandates to trade SDX securities
4. CBDC settlement live at scale: Project Helvetia moving from pilot to operational infrastructure for routine settlement

On this trajectory, ZUG DLT estimates that SDX secondary market volumes will reach CHF 100 million per quarter — a meaningful but still modest level — by 2027 to 2028. Full secondary market development, where SDX tokenised securities trade with liquidity comparable to traditional SIX Swiss Exchange bonds, is more likely a 2030 to 2032 horizon. This is not a pessimistic view: building new market structure takes a decade in any asset class. SDX is on track.

Published by ZUG DLT — Donovan Vanderbilt. zugdlt.com provides independent institutional intelligence on Switzerland’s distributed ledger technology ecosystem.