From Commitment to Transition: How Sustainable Debt Markets Can Help Finance the Net-Zero Economy

In June 2026, the Luxembourg Stock Exchange (LuxSE) hosted the World Federation of Exchanges (WFE) Board meeting for the first time in 47 years and co-hosted this year's WFE Sustainability Conference. Bringing together leaders from exchanges, regulators, investors, policymakers and international institutions, the event provided an opportunity to reflect on the evolving role of capital markets in advancing sustainability and accelerating the sustainable finance agenda.

One message emerged consistently throughout the discussions: sustainable finance is entering a new phase. Over the past decade, significant progress has been made in developing taxonomies, disclosure frameworks and sustainable investment products. The challenge now is no longer simply defining what constitutes sustainable finance, but ensuring that capital reaches the companies and sectors that must transform if global climate objectives are to be achieved.

This shift places transition finance – and, in particular, sustainable debt markets – at the centre of the journey towards a net-zero economy.

From green finance to transition finance

When LuxSE launched the Luxembourg Green Exchange (LGX) in 2016, it became the first exchange in the world to operate a platform dedicated entirely to sustainable securities. Since then, the market has grown significantly. Today, LGX brings together more than 2,300 sustainable bonds from 340 issuers across 60 countries, representing EUR 1.3 trillion raised for sustainable investment projects worldwide.

The growth of green, social and sustainability (GSS) bonds has demonstrated that capital markets can effectively channel investment towards activities that generate positive environmental and social outcomes. Yet the next stage of the transition requires something broader.

Reaching net zero will not be achieved by financing only activities that are already environmentally sustainable. The scale of investment required to decarbonise the global economy means that attention must increasingly turn to the sectors responsible for the largest share of emissions. The success of the transition will ultimately depend not only on financing green activities, but also on supporting the transformation of carbon-intensive sectors that remain essential to economic activity.

Most sectors of the global economy – including heavy industries such as steel and cement, as well as transport, energy and agriculture – must continue reducing emissions while maintaining economic growth and competitiveness. Achieving net-zero emissions will depend in large part on supporting these sectors as they decarbonise over time.

This is where transition finance comes into focus, mobilising capital to support the decarbonisation of emission-intensive sectors through credible and measurable strategies. It reflects a growing recognition that achieving climate objectives depends on transforming the wider economy, not only expanding activities that are already low-carbon.

The discussions in Luxembourg reflected this shift. Investors are increasingly looking beyond sustainable labels to assess whether issuers have robust transition strategies, effective governance and interim targets aligned with recognised climate scenarios. At the same time, the growth of transition finance brings important credibility challenges. Investors need confidence that transition strategies are backed by realistic yet ambitious implementation plans, measurable milestones and robust governance. Maintaining trust will therefore require high-quality disclosures and transparent reporting that distinguish genuine transition efforts from unsupported claims.

Without such credibility, capital risks being directed towards transition pathways that are difficult to assess and even harder to verify. This is why regulators continue to refine disclosure frameworks that encourage capital flows while safeguarding market integrity through greater transparency, comparability and accountability.

The role of sustainable debt markets

Within this evolving landscape, debt markets are uniquely positioned to support the transition to a net-zero economy.

They provide access to capital at the scale required to finance long-term investments in energy, transport, industrial decarbonisation and other transition-related infrastructure. Bond markets have long been an important source of financing for both public and private sector investment, making them well suited to supporting the large-scale capital expenditure associated with the transition.

Debt instruments also align well with transition timelines. Many decarbonisation investments require substantial upfront financing to deliver environmental and economic benefits over many years. The longer maturities available in debt markets can therefore provide financing structures that are better aligned with these investment horizons.

Moreover, sustainable debt markets offer flexibility through a range of instruments tailored to different financing needs. GSS bonds continue to finance eligible projects using dedicated use-of-proceeds frameworks, while sustainability-linked bonds link financing to sustainability performance targets and transition bonds support eligible transition activities.

Taken together, these instruments illustrate how sustainable debt markets have evolved – from financing specific green projects to supporting broader corporate and sectoral transition strategies. This evolution is important because the transition to net zero will be determined less by the funding of a limited number of green projects and more by the successful transformation of entire business models, industrial processes and value chains.

Importantly, sustainable debt markets also promote transparency. Use-of-proceeds reporting, post-issuance allocation and impact reporting, and performance-linked mechanisms provide investors with greater visibility into how capital is deployed and, where applicable, whether agreed sustainability objectives are being met. This transparency is fundamental to maintaining confidence as transition finance continues to evolve.

Exchanges have an important role within this ecosystem, helping to strengthen market integrity by promoting disclosure, improving access to information and connecting issuers with a growing community of investors seeking credible transition opportunities. As providers of market infrastructure, exchanges are also well placed to support greater consistency, comparability and transparency across sustainable debt markets.

Transparency: the example of the Transition Finance Gateway

As transition finance grows, transparency is becoming increasingly important and, in many cases, remains a missing ingredient. Investors are looking beyond individual securities to assess the companies behind them. A sustainable label on a single bond is no longer sufficient in isolation.

Recognising this shift, LuxSE launched its Transition Finance Gateway in July 2025. The initiative reflects a broader reality across sustainable finance: investors increasingly require issuer-level transition information alongside security-level data to assess the credibility of long-term transition pathways.

This initiative brings together publicly available transition-related data for more than 500 non-financial corporate debt issuers listed on the Exchange across both conventional and sustainable bond markets. By integrating data from the Carbon Disclosure Project (CDP), the Net Zero Tracker (NZT), the Science Based Targets initiative (SBTi) and the Transition Pathway Initiative Centre (TPI), the Gateway provides investors with a broader perspective on issuers' transition profiles.

This approach acknowledges that credible transition finance requires looking beyond labels. It involves evaluating corporate strategies, emissions trajectories and alignment with global climate goals. By enabling greater transparency at the issuer level, market infrastructure can help investors assess the credibility of transition plans, make more informed decisions and support the allocation of capital to companies driving genuine decarbonisation.

Looking ahead: from frameworks to outcomes

The discussions at this year's WFE Sustainability Conference demonstrated that the foundations of sustainable finance are increasingly well established. The next challenge is to translate those foundations into measurable economic outcomes.

The success of sustainable finance will ultimately not be measured by the number of frameworks developed, reports published or sustainable instruments issued. It will be measured by the extent to which capital supports real-world decarbonisation and enables the transition of the sectors that matter most.

For sustainable debt markets, this means continuing to strengthen the credibility of transition finance, improving the availability and comparability of data, and supporting innovation that enables capital to reach the sectors where transformation will have the greatest impact.

The transition to a net-zero economy will require coordinated action across governments, companies, investors and market infrastructure providers. Sustainable debt markets will remain central to that effort. By combining scale, transparency and increasingly sophisticated financing solutions, they can help bridge the gap between climate ambition and implementation. The next chapter of sustainable finance will not be defined by commitments alone, but by the ability to finance credible transition pathways and deliver measurable results in the real economy.