We're in uncharted territory when it comes to IPOs. Prior to 2026, the largest IPO in U.S. history was Alibaba (BABA 3.88%), which raised about $25 billion in late 2024 at a market capitalization of roughly $230 billion.

This year, there's a possibility we'll see not one but three companies with trillion-dollar valuations when their shares start trading. SpaceX, Anthropic, and OpenAI are all expected to go public before the end of the year, and the trio could raise $240 billion at a combined valuation of more than $4 trillion.

SpaceX is furthest along in the process. It has already made its S-1 filing public, and its shares are expected to start trading on June 12 at a valuation of about $1.77 trillion. Anthropic is the next in line, having recently filed a confidential S-1, indicating that we're within a few months of its public debut.

Image source: Getty Images.

To be sure, there's a lot we don't know yet, especially when it comes to Anthropic. But based on what we know now, one looks like the more attractive option to me.

What you're buying with each company

SpaceX is the more complex business of the two, with three distinct parts:

• Starlink's satellite internet business, which is the fastest-growing telecom company in history.
• SpaceX's rocket launch business, which has a near monopoly on heavier launches with its Falcon rockets and upcoming Starship.
• The xAI business, which includes the Grok AI tools as well as the X (formerly Twitter) platform.

Starlink itself is highly profitable, but the business is losing money overall. The company produced about $18.7 billion in revenue in 2025 (up 33% year-over-year) and produced a $4.9 billion net loss. However, the company was profitable on an adjusted EBITDA basis.

At its core, Anthropic is a software business. It has emerged as the leader in AI models with its Claude family of products. Claude subscribers include enterprises, developers, individuals, and more, and tools like Claude Code are gaining popularity rapidly.

As mentioned, we don't have all the details about Anthropic's financials, but we do know a lot. The company's revenue run rate was $9 billion at the start of 2026 and has since grown exponentially to $47 billion. The company's leaders expect to generate more revenue in the current quarter than Anthropic produced all of last year.

For both of these businesses, it's difficult to quantify the true market opportunity. SpaceX gave a $28.5 trillion addressable market in its S-1, but this figure includes the entire global broadband market, launch services, AI tools, and even things that don't exist yet, such as data centers in space.

With Anthropic, the generative AI market is growing rapidly, so it's also tough to say. The global generative AI market was estimated at about $54 billion last year and is projected to reach nearly $1 trillion in annual revenue by 2035. If Anthropic can remain a leader (it currently has about 32% of the enterprise market but a small percentage of the consumer market), its potential could be massive.

Does either have a reasonable valuation?

Neither of these IPOs is going to be a cheap stock when they go public, assuming that their share prices trade close to expected IPO valuations. Based on a $1.75 trillion valuation, SpaceX will trade for about 94 times sales, a level that we've never seen with any of the trillion-dollar companies in the market.

Anthropic recently raised capital at a $965 billion valuation, but many experts believe it will command a valuation of $1.2 trillion or more by the time it goes public. Even at this level, Anthropic will be trading for about 25 times sales, and that's for a business whose revenue is growing exponentially. By the time it actually makes its public debut, it's fair to assume that its annual revenue run rate will be significantly higher than the $47 billion it recently revealed.

The verdict: Which one might I buy?

To be sure, both businesses have risks to consider. SpaceX is pricing in significant growth from revenue streams that don't yet exist. Plus, Elon Musk will be in full control thanks to his super-voting shares, and building out the xAI side of the business will require significant capital.

On the other hand, Anthropic is in an ongoing legal dispute with the Pentagon; it faces stiff competition from OpenAI, Alphabet (GOOGL 0.82%)(GOOG 0.80%), and others, and there's a lot we won't know until its S-1 becomes publicly available.

To me, the answer is clear. Anthropic has a valuation based on exceptional revenue growth and is defensible by the actual business momentum, rather than on a potential future growth narrative.

Although I'm watching Anthropic's IPO closely and may add shares to my portfolio, I'm still likely to take a cautious approach. My specific plan could change based on market conditions, but the most likely strategy will be to open a small starter position shortly after the IPO and add incrementally over time, assuming the stock remains attractive and the long-term thesis remains intact.