The Next Generation of Indices: Four Themes Shaping Portfolios in 2026 and Beyond

Investment strategies are increasingly being shaped by structural transformations that cut across traditional sector boundaries. Four themes stand out as defining forces for capital allocation over the next decade: blockchain's evolution into core economic infrastructure, the convergence of artificial intelligence and clean energy, the expansion of private equity beyond public markets, and the maturation of ESG from narrative scoring to precise, data-driven measurement. For each, Euronext has developed innovative indices designed to make the trend investable in a way that existing benchmarks and sector classifications simply cannot.

1. Blockchain: From Speculation to Infrastructure

Blockchain has travelled a long road from its origins in cryptocurrency settlement to its current role as enterprise-grade infrastructure. Ten of the world's largest banks have announced partnerships to develop blockchain-based assets pegged to G7 currencies. Visa now settles the majority of its e-commerce transactions using tokenised infrastructure. According to GlobalData, the global blockchain market is expected to reach $291 billion by 2030.

Yet investing in this trend remains surprisingly difficult. Blockchain is an embedded technology, not a standalone sector, which means traditional sector classifications miss most of the exposure. The ETF market reflects this awkwardness: just six blockchain-themed ETFs currently exist, managing a combined €1.4 billion in AUM, a fraction of the capital chasing adjacent themes. That said, the +13.1% YTD return and €187 million in net inflows recorded by Trackinsight as of 24 April 2026 suggest genuine and growing investor appetite. The gap between interest and investable product is precisely what Euronext is seeking to fill.

Euronext's response is a pair of indices, one for Europe, one for the US, developed in partnership with Impact Cubed, a leading research house estimating the degree to which companies are financially exposed to blockchain. The methodology estimates actual revenue exposure to blockchain across three tiers of involvement, from core infrastructure providers to companies with strategic adoption commitments. The European index is anchored by financial institutions leading on tokenisation and stablecoins (examples include SAP, HSBC, Santander), while the US index captures the broader tech-industrial ecosystem (such as NVIDIA, Amazon, Meta).

"What we want is a diversified portfolio that gives investors exposure to the broad blockchain ecosystem, not just crypto exchanges or miners," says Robin Gallego, Head of Buy Side Index Structuring at Euronext. The index also deliberately captures companies that adopt blockchain, not just those that build it, on the basis that those deploying the technology at scale will ultimately derive the greatest economic benefit.

2. Private Equity: Opening the Gates

The median age of companies at IPO has doubled — from six years in 1980 to twelve years in 2025 (University of Florida research). As growth companies stay private for longer, a rising share of value creation is happening outside public markets. Preqin forecasts global private equity AUM to exceed $20 trillion by 2030.

Regulatory tailwinds are accelerating the trend. Europe's Solvency II framework assigns a capital charge of 22% to private equity versus 39% for listed equities. In the US, the government recently opened 401(k) retirement plans to private equity investment, dramatically widening the potential investor base.

Euronext has launched the Listed Private Equity Index, which tracks 63 publicly listed private equity managers, venture capital firms and business development companies (BDCs) across developed markets.

The approach captures the private equity return premium while preserving daily liquidity — removing the two biggest historical barriers of illiquidity and high minimum investment thresholds.

"We want to do for private equity what passive indexing has done for listed equities — make access easier and more transparent," says Lan Anh Tran, Senior Quantitative Index Structurer at Euronext. The ambition is straightforward even if the execution is not: private equity performance cannot be perfectly replicated through listed vehicles, but by focusing on listed managers and pure-play firms rather than attempting to mimic underlying portfolio companies, the index provides a more faithful and liquid approximation than anything currently available.

3. AI and Clean Energy: A Symbiotic Investment Case

Artificial intelligence and clean energy are no longer separate themes. Training a large AI model can consume hundreds of megawatt-hours of electricity. Global electricity generation for data centres is projected to grow from 460 TWh in 2024 to over 1,000 TWh by 2030, following several major AI players' announcements of nuclear-powered and renewable-energy infrastructure initiatives to meet this surge in electricity demand. The result: access to stable, low-carbon power has become as strategic for AI companies as chip supply.

Thematic ETF investors are already voting with their flows. According to Trackinsight data as of 24 April 2026, alternative energy ETFs have delivered a +24.9% YTD return and attracted €1.9 billion in net inflows, with €11.6 billion in AUM across the segment. Nuclear energy, increasingly seen as the baseload partner for AI infrastructure, has pulled in €1.1 billion in flows this year at a +21.2% YTD return. Hydrogen, benefiting from its role in industrial decarbonisation, leads all clean energy sub-themes at +35.6% YTD. Meanwhile, AI & Big Data ETFs, which manage €9.1 billion, have posted a more modest +10.9% YTD and seen €193 million in net outflows, potentially reflecting a rotation toward more energy-integrated exposures as investors grasp the infrastructure dependency at the heart of AI scaling.

Euronext's Clean Energy & AI Index captures companies across this converging value chain, semiconductors, clean energy generation, and next-generation grid technologies, in a single, unified instrument, reflecting the view that neither theme can be understood in isolation from the other. "There are numerous indices linked to AI, but we saw that AI without energy cannot develop," says Julien Reboutier, Index Structurer at Euronext. "AI needs a lot of stable, renewable energy to support its growth. That's why we have combined both thematics into one index."

4. Quantifying the low carbon transition

The fourth theme is arguably the most technically ambitious. ESG investing has matured past the era of broad, opaque scores. Euronext's new Climate Score methodology integrates four measurable pillars: GHG intensity (current emissions), climate transition score (forward-looking alignment with net-zero pathways), green capital expenditure (actual capital committed to decarbonisation), and an aggregate environmental governance score sourced from Valueco. Critically, the four pillars are combined using a weighted geometric aggregation, which reduces the ability of strong performance in one pillar to mask weaknesses in another.

The Climate Score is then embedded directly into an optimisation process targeting the 300 largest Eurozone companies by free-float market cap, with a tracking error constraint below 2% relative to the underlying benchmark, making it usable for institutional investors with tight risk budgets. The use of geometric rather than arithmetic aggregation is a deliberate design choice. "Some pillars are negatively correlated, and a simple average would mask important weaknesses," explains Lan Anh Tran. "We chose geometric aggregation to reduce the cancellation effect." The result is a framework where a company cannot paper over poor emissions performance with strong governance scores, a meaningful departure from the ESG rating methodologies that have drawn criticism for exactly that flaw.

A Framework for Structural Change

What unites all four themes is a common diagnosis: traditional benchmarks, sector classifications, and ESG frameworks were built for a different era. They are increasingly poorly suited to structural trends that span industries, rely on diffuse revenue exposure, or depend on forward-looking metrics rather than historical performance.

Euronext's new index families are designed not to chase performance but to make long-term structural transformation systematically investable, and ETF flow data suggest that investors are already moving in this direction, even before the right instruments exist to do so efficiently.

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This article is part of an advertising partnership between Euronext and Trackinsight.

Please note this article is for information purposes only and does not in any way constitute investment advice. It is essential that you seek advice from a registered financial professional prior to making any investment decision. All companies or stocks named in the article are solely for illustration purposes and do not represent in any way investment advice.