SpaceX, OpenAI, and Anthropic: The Three Largest Private Company IPOs in History Are Coming in 2026

Three mega-IPOs approaching $3 trillion combined valuation are reshaping capital markets structure and forcing index providers to rewrite inclusion rules.

Photo: Sven Piper / Unsplash

What Is an IPO — and Why Does It Matter?

Before getting into the numbers, it helps to understand the mechanics. An IPO, or Initial Public Offering, is the moment a private company opens its ownership to the general public for the first time by selling shares on a stock exchange like the NYSE or NASDAQ. Before an IPO, only select investors — founders, employees, and venture capital or private equity funds — can own a piece of the company.

When a company goes public, it sells a portion of itself to anyone who wants to buy. The proceeds go to the company (or in some cases to early shareholders), and from that day forward, anyone with a brokerage account can own a share.

The IPO process typically follows a predictable sequence. Most companies start with early private funding rounds — a Series A, B, C, and so on — where they raise capital from venture investors at progressively higher valuations in exchange for equity. Once the company is mature enough and has sufficient revenue or growth trajectory to attract public market investors, it begins preparing for an IPO. That preparation involves hiring investment banks as underwriters, preparing detailed financial disclosures (called an S-1 filing), going on a “roadshow” to pitch institutional investors, and ultimately pricing shares the night before trading begins.

One feature that Bloomberg highlighted in the SpaceX news is the phrase “confidential filing.” Under the JOBS Act of 2012, companies with less than $1 billion in annual revenue can submit a draft registration statement to the SEC confidentially, before making it public. This gives companies time to work through the regulatory process and resolve issues with the SEC privately, without the public scrutiny of a live filing. For SpaceX, a company that still technically qualifies, it means the IPO process can begin behind closed doors before any public disclosure is required. Once a company goes public with its filing, a minimum of 15 days must pass before the IPO can be priced.

Index providers like S&P and FTSE Russell typically have rules around how large a float (the percentage of shares available for public trading) a company must have before it can be included in a major index like the S&P 500. Bloomberg Intelligence noted this week that index providers are now considering rewriting those rules specifically to accommodate the scale of these listings — a sign of just how unprecedented this IPO wave is expected to be.

SpaceX: The Biggest IPO in History

Elon Musk’s SpaceX is targeting a confidential SEC filing as early as March 2026, according to Bloomberg, citing people familiar with the matter. That would put the company on track for a June market debut — and at the reported valuation of over $1.75 trillion, it would shatter every record in IPO history.

For context: the current record holder is Saudi Aramco, which raised $29 billion in its 2019 listing. SpaceX is reportedly aiming to raise up to $50 billion — nearly double that figure in a single offering.

The valuation itself tells a story about how dramatically this company has grown in a short time. SpaceX was valued at roughly $350 billion in a December 2024 tender offer. By July 2025, another tender offer implied a valuation of $400 billion. A December 2025 tender placed it at $800 billion. Then, in February 2026, SpaceX completed its acquisition of Musk’s AI company xAI — a deal that valued the combined entity at $1.25 trillion, with SpaceX at $1 trillion and xAI at $250 billion. The IPO valuation of $1.75 trillion reflects the combined business, and the upward revision since the xAI merger.

At $1.75 trillion, SpaceX would rank among the six most valuable companies on the planet, sitting alongside Nvidia, Apple, Alphabet, Microsoft, and Amazon — immediately upon listing.

What SpaceX actually does: The company operates two core businesses. The first is launch — SpaceX’s Falcon 9 rocket is the world’s most used orbital launch vehicle, and the company accounted for over 50% of all Earth orbital launches in 2025, completing 129 successful missions. Reusable rocket technology fundamentally changed the economics of getting to space; Falcon 9 boosters can now land themselves and fly again, cutting launch costs dramatically. The second business is Starlink, a satellite-based internet service built on a constellation of thousands of small satellites in low Earth orbit. Starlink turned profitable in 2024 and currently serves millions of subscribers globally. SpaceX’s EBITDA margins are estimated at around 50%, roughly double the ~20% margins typical of traditional aerospace companies.

The xAI acquisition adds a third dimension: Musk has indicated the merged company will focus heavily on space-based AI infrastructure, including the construction of AI data centers in orbit. The full IPO proceeds are expected to fund Starship development (the next-generation rocket intended to carry humans to Mars), AI data center construction, and lunar base projects.

Underwriters being considered include Bank of America, Goldman Sachs, JPMorgan, and Morgan Stanley.

Secondary market context: For readers wondering what SpaceX shares trade at today — the answer is complicated. SpaceX is still private, so there is no public stock price. However, platforms like Forge Global operate secondary markets where accredited investors (those meeting specific income or net worth thresholds set by the SEC) can buy and sell shares from employees and early investors who wish to exit before a public listing. As of February 28, 2026, the Forge Price™ for SpaceX stood at $595.51 per share, implying a valuation of roughly $1.4 trillion. In early February 2026, the Forge Price was $550. In December 2025, it was $421. These prices reflect real transactions and market sentiment, but they are not the same as a publicly traded stock price — liquidity is limited, transaction costs are higher, and only accredited investors can participate. The IPO price, when and if it happens, will be set independently and could differ significantly.

OpenAI: $110 Billion and Still Private

The same week SpaceX’s IPO news broke, OpenAI announced it had closed a $110 billion funding round — one of the largest private capital raises in history. The round was led by Amazon ($50 billion), with Nvidia and SoftBank each contributing $30 billion. The round values OpenAI at $730 billion pre-money and $840 billion post-money.

To put that in perspective: OpenAI was valued at $500 billion in a secondary financing as recently as October 2025. It has now added more than $300 billion in implied valuation in roughly four months.

Amazon’s $50 billion commitment comes in two tranches: $15 billion is committed now, with an additional $35 billion to follow “when certain conditions are met” — which, according to reporting by The Information, may be contingent on OpenAI either achieving AGI or completing an IPO by year’s end. As part of the deal, AWS becomes the exclusive third-party cloud provider for OpenAI Frontier, the company’s enterprise agent platform. OpenAI will also expand its existing AWS deal by an additional $100 billion over the next eight years.

The Nvidia partnership involves dedicated access to 3 gigawatts of inference capacity and 2 gigawatts of training on Nvidia’s next-generation Vera Rubin systems. SoftBank’s total stake in OpenAI, including prior investments, now stands at roughly $64.6 billion, representing approximately 13% ownership.

Microsoft notably did not participate in this round, though both companies issued a joint statement saying their partnership “remains strong and central.” Microsoft Azure still serves as the exclusive cloud provider for OpenAI’s APIs, and OpenAI’s first-party products continue to be hosted on Azure.

OpenAI’s user growth supports the scale of this investment. ChatGPT now serves more than 900 million weekly active users and has surpassed 50 million paying subscribers. January and February 2026 are on track to be the largest months for new subscriber additions in the company’s history.

OpenAI has not yet filed for an IPO, but multiple reports indicate the company is targeting a public listing before year’s end. The company is currently not profitable and is projecting roughly $100 billion in cumulative losses between now and 2030, while targeting more than $280 billion in revenue over the same period. The capital requirements are immense — OpenAI is targeting approximately $600 billion in total compute spend through 2030.

OpenAI’s funding history in brief: OpenAI was founded in 2015 as a nonprofit, later transitioning to a “capped profit” structure that limits investor returns to a multiple of their investment. It raised its first significant outside capital from Microsoft in 2019. The company has completed multiple funding rounds since, each at progressively higher valuations, culminating in this week’s $110 billion raise. Microsoft remains the company’s largest historical backer, having committed tens of billions in capital and cloud credits over several years.

The Third Leg: Anthropic

Anthropic rounds out the trio of mega-IPO candidates expected to emerge from 2026. The AI safety company founded by former OpenAI researchers Dario Amodei and Daniela Amodei closed a $30 billion Series G in February 2026 at a $380 billion post-money valuation, following an employee share tender at a $350 billion pre-money valuation. Anthropic has not announced a specific IPO timeline.

Bloomberg noted this week that SpaceX’s filing “would keep it on track for a June listing, making it the first of what could be a trio of mega-IPOs, with OpenAI and Anthropic potentially coming after.” Anthropic is currently the leader in enterprise AI and has been the only commercial AI company with models approved for use across classified Pentagon networks — a status that became dramatically complicated this week (more on that below).

What This Does to the Market

The combined implied valuation of SpaceX ($1.75T), OpenAI ($840B post-money), and Anthropic ($380B) is approaching $3 trillion. Even a partial float of those companies hitting public markets in the same year would be unprecedented in scope.

For context: in 2025, total IPO proceeds across all sectors were approximately $40 billion, with a combined first-day market cap of $442 billion. The peak year for IPO activity was 2021, when total proceeds reached $119 billion. If SpaceX alone raises $50 billion at a $1.75 trillion valuation, it would more than double the single-year IPO proceeds record.

Bloomberg Intelligence flagged this week that index providers including FTSE Russell and potentially S&P are weighing rule changes — including fast-tracked inclusion and relaxed float requirements — specifically to accommodate these listings. If SpaceX lists and is not immediately eligible for S&P 500 inclusion due to float or profitability rules, the scale of the company creates a structural problem for the index itself. Index providers are watching closely.

The Government Contract Picture: OpenAI, Anthropic, and a Week That Changed Everything

The same week these IPO filings crystallized, the landscape for AI government contracts was upended entirely.

To understand what happened, some background helps. The U.S. Department of Defense (now formally renamed the Department of War under the current administration) has been working to integrate commercial AI into classified and sensitive operations. For most of the past year, Anthropic was the only major commercial AI company whose models had been cleared for use on classified government networks, deployed through a partnership with data analytics firm Palantir under a contract worth up to $200 million.

The dispute began over Anthropic’s usage policies. The company had two specific restrictions it insisted on maintaining: no use of Claude for fully autonomous weapons (meaning AI making lethal targeting decisions without a human in the loop), and no mass domestic surveillance of American citizens. The Pentagon’s position was that it needed the ability to use AI for “any lawful purpose” and could not accept contractor-imposed restrictions.

Months of negotiations failed to produce an agreement. On February 27, 2026, the Pentagon set a 5 PM deadline. Anthropic held its position. Dario Amodei, the company’s CEO, stated publicly: “These threats do not change our position.” Anthropic argued that the Pentagon’s final contract language would have allowed its restrictions to be “disregarded at will,” meaning a compromise in name only.

President Trump responded via Truth Social, directing every federal agency to immediately cease use of Anthropic’s technology and stating the government would not do business with the company again. Defense Secretary Pete Hegseth separately announced the Pentagon would designate Anthropic a “supply chain risk to national security” — a designation normally reserved for companies with ties to foreign adversaries. The practical effect: every defense contractor doing business with the Pentagon would be prohibited from also using Anthropic’s products commercially. Anthropic announced it would challenge the designation in court, calling it “legally unsound.”

Within hours, Sam Altman’s OpenAI announced it had struck its own deal with the Pentagon to deploy its models on classified networks. Altman stated that OpenAI’s agreement with the Pentagon contains the same two restrictions Anthropic had been insisting on — no domestic mass surveillance, and no fully autonomous weapons — and that the Department of War agreed to these principles. Altman wrote that those principles are “reflected in law and policy” and were incorporated into the agreement.

The distinction between the two companies’ outcomes appears to lie in how those restrictions were written. Anthropic sought explicit contractual language prohibiting those uses. OpenAI reportedly agreed to an “all lawful purposes” framework, with the restrictions framed as reflecting existing U.S. law and Pentagon policy rather than as contractor-imposed limits on what the government can do. Whether that difference is meaningful in practice remains unclear — CNN, Fortune, and others reported that neither OpenAI nor the Pentagon fully explained how both sides’ positions could simultaneously be true.

Altman publicly called for de-escalation, asking the Pentagon to offer the same terms to all AI companies. OpenAI also has existing contracts with the Pentagon through the government’s Genai.mil initiative. Separately, Musk’s xAI — now merged with SpaceX — became the second company after Anthropic to be approved for use in classified settings earlier this week.

Google also holds Defense Department contracts. The AI government contracting landscape now looks as follows: OpenAI has a new classified network deal and existing Genai.mil access, xAI is approved for classified systems, Google holds existing contracts, and Anthropic is currently banned from all federal government use pending a legal challenge.

What to Watch This Week

SpaceX S-1 watch: A March confidential SEC filing would be the first official confirmation that the SpaceX IPO is real and on schedule. No public disclosure would accompany a confidential filing, but reports from bankers, employees, and regulatory sources will almost certainly surface.

OpenAI IPO timeline clarity: With the $110 billion round closed and Amazon’s additional $35 billion contingent on an IPO by year-end, watch for OpenAI to provide more specific guidance on its listing timeline. A late 2026 IPO would mean a filing in the next few months.

Anthropic’s legal challenge: The company has stated it will challenge the Pentagon’s supply chain risk designation in court. Watch for a formal legal filing. In the meantime, watch whether major enterprise customers or Fortune 500 companies with Pentagon exposure begin reducing Claude usage to avoid compliance risk.

S&P 500 index rule changes: FTSE Russell has already opened a formal consultation on fast-tracking large IPOs. Any signal from S&P that it is considering similar changes would be significant for how SpaceX shares are treated the moment they list.

PCE inflation and rate outlook: The Fed’s preferred inflation gauge prints this morning. A hot reading — following Wednesday’s core PPI surprise of +0.8% — would reinforce the higher-for-longer rate narrative, which would weigh on high-valuation growth and IPO-candidate stocks broadly.