Everyone wants SpaceX, OpenAI and Anthropic. But do you have to too?

2026 is a vintage year for stock market newcomers. SpaceX has just signed for the largest IPO ever, while OpenAI and Anthropic are waiting in the wings for autumn to come. Together, these three companies are likely to represent as much capital as Japan’s GDP (!), the world’s fourth-largest economy. What effect will such a tsunami of money have on the market? And will it also affect your other investments?

1. Who is going public and when?

If everything goes according to plan, three of the world’s largest private companies will go public this year. On 12 June SpaceX (Starlink and xAI) made their debut. It was the largest IPO ever, with the market capitalisation managing to exceed $2 trillion on the very first day (source). By way of comparison, that represents the value of all the goods and services produced by the entire Spanish economy in a single year (GDP).

OpenAI – known for ChatGPT – submitted a filing to the US securities regulator in June. It is aiming for a listing by autumn and a valuation of around $850 billion (source)(source).

Anthropic, the creator of Claude, had submitted its application for an IPO a few days earlier. The listing is planned for October. After a capital round of $65 billion, the company is currently valued at around $965 billion (source).

2. Will these shares automatically be included in most trackers?

For those investing in trackers, the direct impact of these mega IPOs is currently still minimal. It is therefore not the case that these companies will immediately dominate all popular trackers.

The reason lies in how many indices are calculated. They weigh a company according to its free-float shares. SpaceX, for example, floated ‘only’ around 85 billion dollars’ worth of shares (source). If SpaceX were to be included in the S&P 500 immediately, its weighting in the index would be less than 0.5% (source).

Of course, the free float will increase over time. After SpaceX’s first quarterly report is published in August or September, the so-called lock-up period expires; early investors will be allowed (not obliged) to list and sell 20 per cent of their shares on the stock exchange. Additional tranches may be sold at a later date, or as soon as the share price rises by a certain percentage above the issue price (source).

But even that does not mean that SpaceX will be included in the popular S&P 500 any time soon. That index requires four consecutive quarters of profit (source). OpenAI, Anthropic and SpaceX are still burning through money at a rapid rate. A quick inclusion in the S&P 500 is (perhaps) out of the question.. In other words, if you invest in generic index trackers such as the S&P 500 or MSCI World, you should not expect these mega-companies to immediately take up significant positions in them.

The story is somewhat more nuanced for those who have a tracker on the Nasdaq 100, for example. This is because various index providers have accelerated the inclusion period. Nasdaq has shortened the waiting time to 15 trading days. FTSE Russell has even cut it to five days (source). Once included in the index, you indirectly hold the shares as well. You don't decide this yourself. Those who would rather not invest directly in the shares themselves but would still like some exposure will soon be able to obtain just that through various trackers with a strong focus on technology.

3. Are these IPOs siphoning money away from the rest of the market?

There is another factor at play. Money is not infinite. To invest billions in SpaceX (and soon in OpenAI and Anthropic), some investors are selling other holdings. These are often existing growth and tech shares. This can create temporary pressure elsewhere in the market. We saw this happen, for example, with various aerospace shares during SpaceX’s IPO (Virgin Galactic plummeted by 30% - source). So don’t always expect a smooth ride on the stock market around these listings. When OpenAI and Anthropic go public, other shares may (temporarily) come under pressure.

4. ‘Everyone’ wants to jump in. But should you?

Popular IPOs often have a spectacular start. SpaceX proved this with a share price increase of 19% on day one and 20% on day two.

Between 1980 and 2024, IPOs on the American stock market increased by an average of 18.9% on their debut (source). In years when investors are optimistic, that first-day gain can actually be much higher. During the peak years of the dotcom bubble, the average price surge on the first day was exceptionally high: 72.1% in 1999 and 56.3% in 2000. 2020 (41.6%), 2021 (32.1%) and 2022 (48.9%) were also remarkable years thanks to a number of heavily hyped IPOs (DoorDash, Airbnb, Snowflake, etc.)(source).

The key question is whether IPOs will sustain their strong performance after the initial euphoria. Here, Ritter's research offers a sobering perspective.. Investors who purchase an IPO share on the first trading day and hold onto it for a longer period tend to experience lower returns on average. Over a period of three to five years, many IPOs yield a lower return than comparable existing shares or indices (source). Of course, these historical averages are no guarantee of future performance: SpaceX, OpenAI and Anthropic may prove the opposite in the long term.

5. Is this the new dotcom era?

It is very tempting to draw a comparison with 1999-2000. Back then, investors drove every new internet prospect sky-high. Periods when many (larger) companies go public often go hand in hand with euphoria.

The textbook example remains Cisco. In March 2000, it became the most valuable company in the world. At the time, its shares were trading at a price/earnings ratio of around 130. It then plummeted by almost 90%. Cisco did not reach its 2000 peak again until 25 years later (source).

Based on an expected annual turnover of around $18 billion and a stock market valuation of around $2.5 trillion (situation on 16 June 2026), investors value SpaceX at around 139 times the annual turnover. This is extremely high according to most standards: Nvidia is valued at 21.5 times its annual turnover, Microsoft 12.3 times and Apple 6.8 times (source). The share price of SpaceX is primarily a claim on the future, rather than a numerical reflection of the past.

Cisco was not a bad company and its revenue continued to grow for years. It was just that the price investors were paying at the time was far too high. Are SpaceX, OpenAI and Anthropic set for a repeat of 2000? Not necessarily. After the dotcom bubble burst, many companies did indeed turn out to be nothing more than hot air. Even so, over time it became clear that some - such as Amazon - had been valued too conservatively.

Nevertheless, the market today is not without its concerns. Firstly, investments in telecommunications around the year 2000 pale in comparison to the figures seen today for AI infrastructure. Never before has Big Tech spent as much money on infrastructure as it does today. The big boys will be investing around $800 billion together this year, compared to $260 billion in 2024. Their cash reserves are dwindling and the largest tech companies are issuing around $135 billion in debt securities this year. All these expenses have to pay off at some point. The same applies to SpaceX (source).

Secondly, there is the risk of market concentration. Nortel, now bankrupt, accounted for 38% of the main Canadian share index during the dotcom era. At one point, the once-dominant Nokia accounted for 60% of the Finnish market. And recently, the South Korean stock market, which is dominated by two chip manufacturers, fell by 15% in a few days due to investor jitters over AI. The top 10 stocks in the S&P 500 recently accounted for almost 40% of the total market capitalisation, a level not seen since 1965. Today, nine of these companies are also linked to the most popular theme on the markets: AI (source).

Thirdly, there are concerns about circular financing. Nvidia invests in OpenAI, OpenAI buys computing power, which largely runs on Nvidia chips (source). Anthropic and Alphabet (Google) lease billions’ worth of computing power from SpaceX (source). The list goes on. Critics fear that this will artificially inflate turnover and valuations. Conclusion? The IPOs of SpaceX, OpenAI and Anthropic will undoubtedly open a new chapter for the technology sector. But a spectacular debut is no guarantee of an equally spectacular long-term performance. Those who are drawn in by the hype risk paying a lot for expectations that may only be met years later – or never at all. On the other hand, Amazon, Nvidia and Meta were also once expensive growth stories, whose valuations many felt were off track.

In any case, there is no reason for most investors to rush headlong into changing their strategy. Diversification, discipline and a long-term vision remain more important than chasing the latest stock market darlings. History teaches us that not every bandwagon everyone wants to jump on is the one that ultimately goes the furthest.

8 things to consider if you want to invest

• Read the prospectus before investing in a new share.
• Use a limit order for new listings. Newcomers often experience significant volatility on their first day. With a limit order, you set your own maximum price.
• Decide in advance how large your position should be. For average investors, individual shares should remain limited. Ask yourself what you would do if the share price fell by 30%.
• Only invest money that you can do without for a period of at least five years.
• Consider spreading your investment over time.
• Stay alert as the lock-up period nears its end. A fresh supply of shares often puts pressure on the share price.
• Consider an equally weighted index as a counterbalance. Classic trackers such as the S&P 500 rely heavily on big tech and AI giants. An equally weighted variant spreads that risk. Bear in mind, however, that you will then be partly investing against the market.
• Diversify across sectors, regions and themes. No single theme should dominate your portfolio.

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