A few giants off the beaten stockmarket track
By the end of 2025, several tech companies have reached astronomical valuations - even without listing on a stock exchange. Leading the pack is SpaceX, Elon Musk's space company, whose valuation recently hit $800bn, with IPO speculation intensifying. That figure makes SpaceX the most valuable private company in the world. It thus tops OpenAI, the company behind ChatGPT, valued at $500bn, after a share sale in late 2025. At a similar level is Tether, the giant behind the stablecoin USDT, also valued around $500bn.
Just behind, ByteDance - TikTok's owner - is estimated at over $330bn at the end of 2025, buoyed by strong revenue growth. The global excitement around artificial intelligence has also propelled the startup Anthropic (an OpenAI competitor) to a $350bn valuation after a massive funding round. London-based fintech Revolut saw its private valuation jump to 75 billion by late 2025 - far more than many listed banks - after a new share sale to investors. These giant "unicorns," each worth tens or even hundreds of billions, thus remain outside public markets for now.
Why stay out of public markets?
Several factors explain why these record-valued companies have not (yet) taken the plunge. First, the abundance of private capital in recent years enables them to fund themselves without tapping public markets. Giant funds (venture capital, sovereign wealth funds, large institutional investors) have eagerly poured billions into AI, space and fintech, convinced of the sectors' potential. "The influx of capital into private markets in recent years has given companies the flexibility to stay private longer - sometimes indefinitely"notes Morgan Stanley.
In short, rather than endure stockmarket swings, these companies prefer to control the timetable. Elon Musk, for instance, has said he would only make SpaceX public once Starlink's revenues are sufficiently predictable and stable. According to the Wall Street Journal and The Information, the US giant is considering an IPO in late 2026.
Likewise, the political or regulatory backdrop can slow a listing: ByteDance faced pressure from US authorities demanding the divestment of TikTok's US operations, making any IPO risky until the dispute was resolved.
Another major reason: maintaining control. Remaining private allows founders and executives not to dilute their decision-making power. Without answering to a multitude of public shareholders, they can pursue a long-term vision. They avoid the pressure of quarterly results and the transparency requirements that come with being listed. For example, OpenAI - structured as a capped-profit company - can invest heavily in AI research without fearing the immediate reaction of shareholders seeking short-term profits.
Similarly, ByteDance or SpaceX can steer investments (into audacious projects like Mars colonization for SpaceX, or in-house AI chips for ByteDance) without the level of public scrutiny a listing would bring. Confidentiality around strategic financial data (margins, R&D spend, etc.) is also an advantage: these companies do not have to disclose everything publicly, which protects them against competitors.
The benefits of staying private
Beyond cyclical reasons, these giants derive structural benefits from staying private. First, they tap colossal private financing that spares them the constraints of an IPO. OpenAI is a striking example: in 2023-2025, the AI startup raised unprecedented sums, notably via a $6.6bn share sale to investors including SoftBank and others, propelling its valuation to $500bn. Anthropic also raised $13bn in a round led by Google, Amazon and others, doubling its valuation in a few months.
It has never been easier for unlisted companies to raise such sums - a sign that private equity and large funds see them as bets just as strategic as any listed stock.
Second, staying private lets them avoid market volatility and the risk of a botched IPO. Recent history offers stark counterexamples: WeWork, once valued at $47bn in private markets, nearly went public in 2019 before revelations about its losses and chaotic governance scared off investors. The result: its 2021 SPAC merger led to near-bankruptcy in 2023 - the stock was worth only a few cents and the valuation collapsed to under $300m. The giant unicorns of 2025 intend to avoid such a fate by not rushing to the trading floor until their models are mature.
A crucial advantage of private status also lies in flexibility for employees and early shareholders. To attract and retain talent, these companies grant stock options or shares to their teams - which only gain concrete value upon a liquidity event (IPO or acquisition). Aware of this, many organize controlled internal share sales, offering "liquidity valves" without going public. Revolut, for example, has already allowed employees to sell shares five times, creating real fortunes for early staff.
ByteDance has set up semiannual buybacks of its own shares to let teams monetize part of their holdings. Most of the time, these buybacks are financed by third party investors: SpaceX and OpenAI use external funds to repurchase employee shares. ByteDance, thanks to its profitability, stands out by drawing on its own cash for these buybacks - a sign of healthy margins and rare financial independence.
This strategy brings a double benefit: it keeps employees motivated (they see the value of their work turn into wealth) while avoiding the pressure of a public float. By staying private longer, 84% of employees consider equity participation an effective motivator, provided there is an organized liquidity window at some point. Thus, unlisted giants combine the best of both worlds: total strategic freedom and internal mechanisms to let shareholders and employees benefit from growth..
Drawbacks and risks of a long wait
However, remaining indefinitely outside public markets comes with trade-offs and risks. First, these stratospheric valuations are set in relatively opaque, illiquid private trades. The absence of a price discovered on an open market carries the danger of persistent overvaluation: only the test of public markets would confirm or disprove the true value. WeWork illustrated the brutal gap between fanciful private valuations and market reality.
Even for today's champions, a downturn could dampen private investors' enthusiasm and trim valuations before any IPO. Moreover, delaying a listing does not postpone public scrutiny forever: when SpaceX or OpenAI decide to go public, they will face the same demands for profitability and transparency as any listed company. And the later the IPO, the larger the company - and the higher the bar to win over the broader public. Shein, for example, is targeting $2bn in net profit in 2025 to reassure the market ahead of a potential IPO, after having to scale back its valuation ambitions. Each quarter without a listing lengthens the wait for early investors seeking returns: pressure for an exit eventually builds, especially for venture funds with finite lifecycles.
Finally, remaining private means managing a limited but demanding shareholder base. Behind-the-scenes negotiations with major investors can intensify if results disappoint or strategic rifts emerge - tensions that would otherwise be arbitrated by the stock market once listed. The recent OpenAI case showed this: despite blistering growth, the governance of an unlisted company can be shaken overnight (the ouster and swift return of its chief in late 2025) under pressure from private shareholders and tech partners. This complex internal governance, combined with a lack of public visibility, can unsettle business partners and regulators. By contrast, a listing imposes stricter governance rules and reassures through regular financial disclosures.
Are they heading for an IPO?
The question is not if, but rather when these private titans will eventually go public. Many analysts expect most of these companies will have to take the step sooner or later, if only to keep growing. SpaceX has already hinted at a possible IPO in 2026, encompassing the Starlink business, to capitalize on its dominance in space. Revolut could seek a listing once it secures its UK banking license, to build trust with the public and regulators. Shein, after navigating trade headwinds, will probably list in Hong Kong or New York to finance its global expansion. OpenAI and Anthropic, whose technologies are reshaping the economy, could remain private as long as Big Tech (Microsoft, Google, Amazon) backs them behind the scenes - but an IPO would give them a currency (stock) for potential acquisitions and greater credibility with enterprise customers.
In the meantime, these invisible stockmarket giants continue to weigh heavily on the global economy without appearing in market indexes. Their strategic choices - to stay private or open up to the public - will have major consequences. For the financial ecosystem, watching these leaders remain off-market raises questions about value creation being captured by a few insiders: colossal gains are currently realized in private markets, denying ordinary savers the chance to invest in the most dynamic companies. Conversely, their potential arrival on public markets could bring a breath of fresh air and optimism to exchanges sometimes short of new locomotives. In any case, the line between private and public has never been more blurred - and will remain so as long as the exceptional conditions last that let these titans thrive far from Wall Street's spotlight. The challenge will be to find the right timing: preserving as much as possible the control and long-term vision that made them successful, while one day offering an honorable exit to those who believed in them from the outset.
