4 Lessons for Future OpenAI and Anthropic Investors, Following SpaceX's Historic IPO

SpaceX (NASDAQ: SPCX), the aerospace and AI company founded by Elon Musk, went public on June 12 at a valuation of $1.77 trillion, making it the largest IPO in history. It went public at $135 per share, started trading at $150, and hit a record high of $225.64 on June 16.

But as of this writing, SpaceX's stock trades at about $160. Many investors who hopped on the bandwagon in its first four days are now underwater. That volatile market debut should teach investors four valuable lessons about hot IPOs like SpaceX -- and how they should approach OpenAI and Anthropic, two of the market's most eagerly anticipated AI IPOs, in the future.

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1. Valuations matter

When SpaceX went public, it was already valued at 95 times its 2025 revenue of $18.7 billion. At its peak market cap of $2.66 trillion, it was valued at 142 times its trailing sales. Those were sky-high valuations, even for a company that grew its revenue by 33% in 2025. As of this writing, SpaceX is worth $2.1 trillion, or 112 times last year's sales.

OpenAI was most recently valued at $852 billion, and its founders hope to go public with a market cap of $1 trillion. That would be 50 times its annualized revenue run rate of $20 billion at the end of 2025, making it seem more reasonably valued than SpaceX.

Anthropic, valued at $965 billion after its latest funding round, only had an annualized revenue run rate of $9 billion at the end of 2025. If it's also targeting a $1 trillion IPO, it would debut at 111 times its annualized revenue -- making it more comparable to SpaceX.

2. Profits matter

SpaceX was actually profitable in 2025, as Starlink's profits offset its space division's losses. But this year, it acquired xAI (which owns Grok and X) in an all-stock acquisition before its IPO. After recasting its 2025 financials to account for that acquisition, it became deeply unprofitable. The critics claimed that Musk was bailing out xAI at the expense of SpaceX's shareholders.

OpenAI and Anthropic -- which are both unprofitable -- will also be closely scrutinized when they go public. OpenAI is still racking up steep losses, but Anthropic's rapid expansion in the enterprise market (with tools like Claude Code) is quickly reducing its operating losses. Anthropic even expects to post its first adjusted operating profit this year.

So even though Anthropic might go public at a higher price-to-sales ratio than OpenAI, its clearer path toward profitability might attract more investors. OpenAI, which posted a net loss of $38.5 billion on just $13.1 billion in revenue in calendar 2025, faces a tougher uphill battle.

3. The float matters

SpaceX floated just 4% of its shares in its IPO. That low supply, along with the market's record demand, fueled its initial rally. It also enabled Elon Musk, who still holds a voting stake of up to 85% through his super-voting shares, to maintain firm control of the company.

In other words, investors are paying a premium to own a tiny sliver of SpaceX and never have a voice in its business decisions. SpaceX will also continue to dilute those investors by issuing more shares to cover its acquisitions and stock-based compensation expenses.

OpenAI and Anthropic plan to follow the same playbook by floating 5%-10% of their shares. Therefore, both stocks could experience volatile market debuts -- and investors shouldn't expect any big institutional investors to sway their business strategies.

4. Retail investors matter

Last but not least, we should see if OpenAI and Anthropic deliberately offer their shares to retail investors. SpaceX offered more than 20% of its shares directly to retail investors, generating significant market hype among smaller investors ahead of its market debut.

Some investors might think that SpaceX was "democratizing" the IPO process by allocating more shares to retail brokerages. Still, I believe it was to offset the lower demand from institutional investors who were wary of paying nearly 100 times sales for an unprofitable company. Investors should be cautious if OpenAI and Anthropic do the same thing.

Leo Sun has no position in any of the stocks mentioned. The Motley Fool has no position in any of the stocks mentioned. The Motley Fool has a disclosure policy.