Best IPO Stock to Buy and Hold: SpaceX, Anthropic, or OpenAI?

For investors who like that "new stock smell," this could be the greatest time ever. Several of the most highly anticipated initial public offerings (IPOs) in stock market history have either recently been conducted or are right around the corner.

Space Exploration Technologies' (NASDAQ: SPCX) IPO on June 12 lived up to the hype. Anthropic, which developed the powerful Claude AI model, filed a confidential S-1 initial registration document with the U.S. Securities and Exchange Commission (SEC) on June 1. ChatGPT creator OpenAI submitted its S-1 around May 22.

Which of these three is the better IPO stock to buy and hold? Here's how SpaceX, Anthropic, and OpenAI stack up against each other.

Image source: Getty Images.

SpaceX: The biggest IPO ever, but an astronomical valuation

SpaceX's IPO price valued it at roughly $1.8 trillion. However, the stock soared after going public. SpaceX's valuation topped $2.4 trillion as of early trading on June 19, 2026, making it the sixth-largest company by market cap.

It's no surprise that SpaceX's prospects have excited investors. The company's Starlink unit pioneered the satellite internet service market. SpaceX dominates the launch market with its Falcon 9 rockets. Its Starship vehicle is designed to transport humans to the Moon and Mars.

Much of SpaceX's massive estimated total addressable market of $28.5 trillion, though, is related to its xAI artificial intelligence (AI) business. xAI developed the Grok AI model. It also has recently signed mega-deals to provide compute capacity to Anthropic and Alphabet's (NASDAQ: GOOGL) (NASDAQ: GOOGL) Google Cloud.

The big knock against SpaceX, though, is that many analysts don't think its astronomical valuation is justified based on its growth prospects. For example, Morningstar (NASDAQ: MORN) estimates SpaceX's fair valuation is about 66% below its current share price. There are also governance concerns, given that Elon Musk controls over 80% of the company's voting power.

Anthropic: Skyrocketing revenue, but several question marks

Anthropic was founded in 2021. Its revenue run rate reached $14 billion by February 2026. As of May 28, 2026, the company's revenue run rate had topped $47 billion. And Anthropic's valuation neared $1 trillion.

Claude, the large language model (LLM) developed by Anthropic, has taken the world by storm. It currently ranks as the top AI model across multiple fronts on Vellum's LLM Leaderboard. Claude remains the only frontier AI model that's available on all three of the top cloud platforms.

Anthropic's valuation appears more justifiable, based on its stellar revenue growth, than SpaceX's. However, the company incurs tremendous expenses to build the AI infrastructure needed to support its growth.

Detailed financial information isn't available yet for Anthropic. But CNBC recently reported that the company could generate its first profit in the second quarter of 2026. We'll know more soon about Anthropic moves forward with its anticipated IPO over the next few months.

OpenAI: A super-successful product, but huge expenses

OpenAI is the company that fired the shot heard 'round the world with its launch of ChatGPT in late 2022. ChatGPT became the fastest-growing consumer application in history, reaching 100 million active users in just two months.

Like Anthropic, OpenAI continues to deliver impressive revenue growth. Within the first year after the launch of ChatGPT, the company's revenue hit $1 billion. By the end of 2024, OpenAI was generating $1 billion in revenue every quarter. As of March 2026, it was raking in $2 billion per month.

Also like Anthropic, though, OpenAI must invest heavily to support its growth. But its situation appears to be more challenging than its rival's. Leaked financial documents, verified by the Financial Times, showed the company posted a loss of $38.5 billion last year on revenue of around $13.1 billion.

One other thing to note about OpenAI is that it was originally founded as a nonprofit organization. It's now a public benefit corporation. The nonprofit OpenAI Foundation will continue to have significant control over the company even after it lists its shares on a stock exchange.

Best IPO stock to buy and hold

For now, SpaceX is the only IPO stock that investors can buy and hold. However, I think that the stock could pull back sharply later this year once insiders can sell their shares. My view is that waiting for a more attractive valuation before investing in SpaceX makes sense.

The S-1 filings for Anthropic and OpenAI (which haven't been released to the public yet) should be informative about evaluating the strength of these two AI companies. Assuming its planned valuation isn't outrageously high, I suspect Anthropic could be the best overall pick. I like the company's revenue growth and its prospects. Anthropic is the IPO I'm most anticipating.

Keith Speights has positions in Alphabet. The Motley Fool has positions in and recommends Alphabet. The Motley Fool has a disclosure policy.