Megacap IPOs in 2026:

Implications for benchmarks and passive index strategies  

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Article Type
Market Updates
Topic
Opinion
Published
April 07, 2026
Read time
8 mins
Authors
Jordy Hermanns, CFA
Jacob Vijverberg, CFA
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After a subdued IPO market in 2025, multiple indicators suggest 2026 could bring a “catch up” wave of listings — and not just any listings. A backlog of very large, venture-backed private has been widely discussed as potential IPO candidates, and their eventual entry into public markets could reshape index composition.

 

Key summary

 

  • A renewed IPO cycle in 2026 could include several exceptionally large, primarily US‑based listings, including companies such as SpaceX, OpenAI and Anthropic.

  • If realized, these IPOs would rank among the largest equity listings in history and could materially affect equity index composition.

  • Index providers may further adapt inclusion rules to facilitate faster entry of very large IPOs.

  • This would likely reinforce existing trends in global equity benchmarks, including higher concentration, a stronger US weight, and increased exposure to the Technology and AI‑related sectors.

  • Europe is largely absent from this pipeline of ultra‑large IPOs.

  • These developments raise questions around diversification, concentration risk, and benchmark design.

 

1. The possible IPOs: who is on the radar?

 

The headline candidate: SpaceX: Public reporting suggests that SpaceX is considering a potential IPO, with transaction sizes and valuations that would place it among the largest equity listings ever. Market discussions have referenced valuations well above USD 1 trillion, although no formal timetable or structure has been confirmed. Should such an IPO materialize, it would surpass the scale of historically large listings such as Saudi Aramco in 2019.

 

“AI megaIPOs”: OpenAI and Anthropic: These companies are potential IPO candidates at some point in 2026, with last reported valuations in the hundreds of billions.

 

A broader cohort of large venture-backed companies: Other companies that might be eyeing a public listing financial companies Stripe and Revolut. Also defense stocks are rumored to consider or prepare for listings.  

 

These IPOs, especially SpaceX, OpenAI and Anthropic, truly stand out – with their Galactic size. The valuations being discussed are exceptionally high by historical standards, particularly for companies transitioning directly from private ownership to public markets.

 

Galatic IPOs in the pipeline

 

Note: Selection of anticipated- and rumored IPOs. Indicative valuations based on public market estimates and private funding rounds. Subject to change. Source: Aegon AM, Bloomberg. Data as of Apr-2026. For illustration purposes only.

 

If even a handful of these companies were to enter public markets, 2026 could go down as a record year for U.S. IPOs. Individually, these listings would be comparable in size to the total IPO volume of an entire calendar year. This is largely driven by the exceptionally high valuations being discussed.

 

Galatic IPOs in the pipeline (vs history US IPOs)

 

Note: 2026 estimates are indicative valuations based on public market estimates and private funding rounds and on possible free-float expectations. SpaceX expected at 75billion and OpenAI and Anthropic estimated at 10% free-float. Subject to change. Source: Aegon AM, Bloomberg. Data as of Apr-2026. For illustration purposes only.

 

Estimates suggest that SpaceX alone is valued at close to USD 1.75 trillion — a figure that exceeds the combined market capitalisation of Europe’s largest listed companies, including LVMH, ASML, Hermès, Inditex and L’Oréal. This comparison highlights the extraordinary scale of the proposed listing and underscores just how exceptional these potential Galactic IPOs would be by historical standards.

 

SpaceX is out of this world

 

Note: SpaceX estimates are indicative valuations based on public market estimates and private funding rounds. Subject to change. Source: Aegon AM, Bloomberg. Data as of Apr-2026. For illustration purposes only.

 

2. Passive investing and IPOs

 

In the past years, the assets that are passively invested have grown in size, and many investors, institutional and retail alike, are invested in product that (partially) follow their benchmarks. That begs the question how the key benchmarks treat IPOs. Generally, benchmark rules prescribe minimum requirements for equities to be included in the benchmark. Important factors include the free-float and “seasoning periods”, requiring a minimum amount of trading days after an IPO before being eligible for index inclusion.

 

Now, with mega IPOs in the pipeline, popular benchmark providers might change their index rules and have launched consultations on shortening or removing seasoning periods, and on lowering or removing minimum float thresholds. By allowing “fast entry” investors in these indices would get exposed to these stocks.

 

If large IPOs are added faster, index-tracking strategies can become mechanical buyers very soon after trading begins. Under a “fast‑track” regime for mega IPOs, passive funds linked to major U.S. benchmarks could represent tens of billions of dollars of automatic demand, potentially a significant share of the IPO float.

 

3. MSCI Indices

 

Anticipating a busy IPO year, we have analyzed the impact on our passive global equity mandates. These mandates track the MSCI All Country World Index – a popular index widely used by institutional investors. Although it is difficult to foresee which companies will come to the market, at what valuations and at which free-float, the direction of travel is clear.

 

Currently, MSCI’s index rules would not result in a fast track inclusion, and in fact inclusion would occur at the quarterly rebalancing events, following standard procedures. Still, that means that it is likely that during 2026 the composition of the equity funds will change.

 

Even when using conservative estimates, after inclusion the indices will tilt further towards US, lifting the country weight towards 63%, all else equal. On a sector basis, the index will become more IT heavy.

 

This warrants the question how much diversification is favored, either geographically, sector- or market-capitalization based. At the same time, this is also the moment to review exclusion policies. This allows for a timely assessment of sustainability and exclusion criteria, so that in case of fast entry, policies can be updated timely.

 

4. Europe: a different market (and IPO) landscape

 

The majority of prospective mega‑IPOs are expected to list in the US, reflecting both the geographic origins of these companies and the depth, liquidity and valuation premia that make US equity markets attractive for IPOs. Some non‑US firms, such as Revolut and Canva, are also reported to be considering US listings for these reasons.

 

While Europe remains an active IPO market, it lacks companies of the scale currently discussed in the US. Ultra‑large listings with valuations in excess of USD 1 trillion — or free‑float market capitalisations of USD 50–100 billion — would stand out even more in a European context than in US benchmarks.

 

Eurostoxx 50 constituents (with hypothetical comparison)

 

Note: Chart based on market capitalization. SpaceX expected at 75billion and OpenAI and Anthropic estimated at 10% free-float. Source: Aegon AM, Bloomberg. Data as per Apr-2026. For illustration purposes only.

 

Nonetheless, Europe has seen a handful of IPOs already in 2026, with some more interesting IPOs expected. These rank nowhere close the Galactic in terms of valuations and market-capitalization, but have a decent size – from a European perspective.

 

Netherlands: not bad, but nowhere close US markets

 

  • The listing of defense company Czechoslovak Group (CSG) that listed in Amsterdam in January, at a market capitalization of 25 bn euro. The IPO raised 3.8 billion euro, making it the largest IPO for a defense company ever and the largest IPO in Europe since Porsche's listing in 2022.

  • Earlier this year, the Magnum Ice Company spun off from Unilever and listed in Amsterdam at a market capitalization of 8 bn euro.

 

Defense: renewed momentum sparks listing boom

 

  • Beyond CSG, additional defense companies are reportedly exploring IPOs, including KNDS, which is expected to pursue a dual Paris‑Frankfurt listing.

 

Differences with the US

 

  • The contrast between US and European IPO pipelines reflects structural differences in sector composition, particularly the dominance of large‑scale technology and AI companies in the US. While Europe has promising innovators — such as Mistral AI — their valuations remain materially smaller than those of US peers.

  • Importantly, market size and concentration do not determine investor returns. Smaller or less concentrated markets may offer different diversification characteristics and risk‑return profiles, underscoring the continued relevance of global diversification.  

 

 

Important information

Authors

Jordy Hermanns, CFA
Portfolio Manager
Jordy Hermanns, CFA, is a portfolio manager in the multi-asset group and serves as an investment strategist in the asset allocation team. Jordy is responsible for strategic and tactical asset allocation decisions on the asset allocation team.  
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Jacob Vijverberg, CFA
Asset Allocation Lead
Jacob Vijverberg, CFA, is the asset allocation lead for the multi-asset team, responsible for both strategic and tactical asset allocation, and co-portfolio manager of the Aegon Global Diversified Income Fund. He also provides macro-economic analysis to internal and external stakeholders.  
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