Can the stockmarket swallow Anthropic, SpaceX and OpenAI?

For most of the post-war era, the deal between a great technology company and the public was simple. Build something useful, grow it on venture money, and then — once you were too big for private capital alone — list on a stock exchange and let ordinary investors share in the ride. Microsoft did it. Apple did it. Google did it. Even Facebook, after some hesitation, did it.

Today's most talked-about technology companies are quietly tearing up that script. Anthropic, SpaceX and OpenAI are now among the most valuable businesses on the planet, yet none of them trade on a public exchange. As The Economist recently asked in a piece pointedly titled "Can the stockmarket swallow Anthropic, SpaceX and OpenAI?", the question is no longer whether these firms could list — it is whether public markets, even at their record-breaking size, could digest them if they ever did.

For Australian investors, who tend to access global tech through ETFs and a handful of US-listed mega-caps, the implications are uncomfortable. The defining companies of the next decade may sit permanently out of reach.

The private capital tide that changed everything

The simplest explanation for why Anthropic, SpaceX and OpenAI haven't listed is also the most boring one: they don't have to.

Two decades ago, a company burning through billions to build a foundation model or a reusable rocket would have hit a wall. Venture funds were too small. Sovereign wealth funds rarely wrote that kind of cheque. Hedge funds didn't touch unlisted equity. To keep growing, you needed an IPO.

That world is gone. Pools of late-stage private capital — from Saudi and Emirati wealth funds, Japanese conglomerates, Big Tech treasuries and crossover hedge funds — are now so deep that a frontier AI lab can raise tens of billions without ever filing an S-1. Capital Brief's piece "On Claude nine" captures the giddy mood around Anthropic in particular: a company whose valuation keeps re-rating upwards every few months on the back of private rounds, customer revenue and partnerships with hyperscalers like Amazon and Google.

Why submit to quarterly earnings calls, activist investors and SEC disclosures when Microsoft, Nvidia or a Gulf sovereign fund will hand you a fresh cheque on terms you write yourself?

Big, but maybe too big to list cleanly

Here is where The Economist's framing becomes interesting. If Anthropic, OpenAI and SpaceX were valued at a few hundred billion dollars between them — comparable to a single mature US tech firm — slotting them into the public market would be trivial. They are not.

Each is now valued at sums that, individually, rival the largest companies on the S&P 500. A simultaneous listing of all three would suddenly add a chunk of new mega-cap supply to a market already dominated by a handful of AI-exposed names. Index funds would have to buy. Active managers would have to decide whether to underweight Nvidia or Microsoft to make room. Liquidity would have to be found from somewhere.

And that is before considering that public markets are already, by some measures, stretched. Barron's recently asked plainly: "Is this a stock market bubble? Indicators are flashing red." The piece points to concentration in AI-linked names, lofty multiples and feedback loops between private valuations and public optimism. Adding three more enormous, loss-making or capital-hungry AI/space stories on top of that does not obviously make the market more stable.

What founders learned from watching others list

There is also a cultural shift at play. Sam Altman, Dario Amodei and Elon Musk have all watched what happens to founders who go public.

Staying private lets these companies keep their unusual capital structures — OpenAI's capped-profit model, Anthropic's long-term benefit trust, SpaceX's founder supervoting — intact. Listing would force a tidy-up that none of them seem to want.

What this means for ordinary investors — including Australians

This is where the story stops being abstract. If the most consequential companies of the 2020s never list, retail investors are locked out of the upside in a way that hasn't really been true since the 1990s.

For Australians, the gap is particularly stark. The ASX has no domestic equivalent to a frontier AI lab. Exposure to US tech is typically taken via:

That last channel is the one to watch. Large industry funds — AustralianSuper, Aware, Hostplus — have the scale to participate in late-stage private rounds in a way an SMSF investor simply cannot. If you have super, you may already have a sliver of indirect exposure to companies like SpaceX or Anthropic without realising it. If you are trying to buy in directly through a broker, you have almost no options.

Secondary marketplaces in the US allow accredited investors to trade pre-IPO shares, but Australians face additional regulatory and tax friction. Tender offers run by the companies themselves are typically limited to current and former employees.

Three scenarios from here

The honest answer to The Economist's question is that nobody knows. But the plausible paths narrow to three:

1. They list, eventually, and the market absorbs them

History suggests markets can stretch further than sceptics think. Saudi Aramco's listing was supposed to be impossible. So was Alibaba's. If AI revenue scales the way bulls expect, a staggered IPO of OpenAI or Anthropic in the late 2020s is conceivable — possibly via direct listing rather than a traditional book-build, to minimise dilution.

2. They stay private indefinitely

If private capital keeps flowing and the founders keep resisting, these companies could remain unlisted for a decade or more — entrenching a two-tier system where institutional and ultra-wealthy investors get the upside and retail investors get the index.

3. The bubble pops first

The scenario implied by Barron's. If AI revenue disappoints, or interest rates stay higher for longer, the marginal private investor disappears and these companies are forced to list at lower valuations — or merge into existing public giants. Microsoft already effectively owns a large share of OpenAI's economics; Amazon and Google have similar arrangements with Anthropic. The "acquisition by stealth" is already underway.

The quiet redistribution of who owns the future

Whichever path plays out, something important has already happened. The pact between transformative companies and the investing public has been rewritten without much public debate. The companies building the tools that may reshape work, defence and scientific research are accountable to a small circle of private backers — not to the broader market.

For Australian investors, the practical takeaway is unsentimental: assume the next Microsoft will not arrive on your brokerage screen the way the last one did. Exposure will increasingly come through indirect channels — super funds, hyperscaler shareholdings, niche listed vehicles — or not at all. The stockmarket may yet swallow Anthropic, SpaceX and OpenAI. But it is just as likely they swallow a piece of it first.

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