Do Mega-IPOs From Companies Like SpaceX, OpenAI, and Anthropic Mark a Changing Relationship Between Public and Private Markets?

Yes. The expected mega-initial public offerings (IPOs) from SpaceX, OpenAI, and Anthropic will mark an important shift from private capital dominance toward broader public ownership, with implications for index composition, valuation, liquidity, and investor access to frontier technologies. Their significance lies less in their headline valuations than in what they reveal about the evolving boundary between private and public markets. These listings will broaden public access to transformational companies, but at a stage when private investors already have captured significant upside.

The implications for public equity indexes are meaningful. Together, these companies are expected to list at a combined valuation approaching $4 trillion, more than the total amount raised in all IPOs during the entire dot-com era. While the initial free float for each is likely to be far smaller, ¹ index requirements have either already been waived, or are likely to be waived, so these firms could enter major indexes relatively quickly. Over time, as floats and index weights increase, OpenAI and Anthropic would further expand the large weight of technology in public benchmarks, while SpaceX could blur traditional sector lines across industrials, communications, and technology. Their addition could also make expensive parts of the market look richer still. None of the three companies are yet profitable, and SpaceX’s targeted $1.75 trillion valuation would equate to roughly 100x its 2025 revenues.

Public market investors will gain access to the leading artificial intelligence (AI) franchises and the dominant private space and satellite communications platform. But by the time these companies list, much of the earliest and most explosive upside may already have accrued to private investors. That points to how the financing model for innovative companies has changed. Previous generations of high-growth firms often went public relatively early to fund expansion; today’s largest private companies can remain private much longer because they have access to enormous pools of capital. OpenAI raised more than $120 billion in a private round earlier this year, and Anthropic is reportedly raising about $30 billion privately. As a result, these IPOs are not just about raising capital but also about providing liquidity, establishing transparent price discovery, and broadening the shareholder base. Public markets are no longer the first engine of scale for companies like these, but they remain the main venue for liquidity, governance visibility, and wide ownership.

These offerings could affect the broader IPO market by drawing capital away from other new issues. While Anthropic has not yet filed, SpaceX and OpenAI are each rumored to be seeking at least $60 billion in IPO proceeds, more than double the previous US record set by Alibaba in 2014. In any issuance window, investors have finite risk budgets, portfolio capacity, and attention. Offerings of this size could dominate the calendar and lead investors to fund participation by trimming allocations elsewhere. Even so, Goldman Sachs expects total equity issuance in 2026 to be around $600 billion, including IPOs, which would still amount to less than 1% of US equity market capitalization. That suggests the broader market should absorb these deals without major dislocation, even if they temporarily crowd out smaller offerings.

For venture investors, the implications are more nuanced. Successful IPOs could boost fund-level marks and eventually help convert paper gains into realized distributions, though liquidity may be more gradual because initial floats are small and, at least in SpaceX’s case, tiered lock-ups would make some future sales partly dependent on stock performance. Because funding in these companies has been so concentrated, their IPOs could further widen the gap between top- and bottom-performing venture funds, reinforcing the importance of manager selection. They may also influence future capital deployment by requiring some funds to cast a wider net. Five companies, including OpenAI and Anthropic, accounted for more than 80% of US venture funding in first quarter 2026. Subject to tax and cost considerations, some investors may wish to consider hedging arrangements for what may end up being outsized single positions. For taxable investors specifically, there may be additional options to diversify risk and offset or defer taxes, including direct indexing or extension strategies.

Overall, these mega-IPOs matter less because of the immediate size of their public floats than because of what they signal about valuation, liquidity, and capital formation. Their small initial floats should limit near-term market impact, but their rich valuations raise the risk that public investors gain access only after much of the upside has been captured privately. And while the offerings are likely to be digested by the overall market, their prominence may crowd out other issuers in the near term. For venture investors, that creates both tailwinds and headwinds: stronger marks, realizations, and distributions for the best-positioned funds, but also greater concentration risk and a tougher environment for other portfolio companies seeking to go public.

Footnotes

1. For example, SpaceX is expected to raise less than 5% of a targeted $1.75 trillion market cap.