SpaceX Investors Just Got Some Bad News From Anthropic Founder Dario Amodei

Last weekend, Anthropic chief executive Dario Amodei published a blog post calling for a slowdown in the pace of artificial intelligence (AI) development. He is worried this technology is progressing so fast that we might lose control over it, and he highlighted a series of recent cybersecurity events as evidence.

In May, Anthropic signed a massive deal to rent computing capacity from Elon Musk's Space Exploration Technologies (NASDAQ: SPCX), which could be worth tens of billions of dollars over the next few years. SpaceX stock is trading at a sky-high valuation because investors are pricing in future revenue from this deal (and other similar deals), but a slowdown in AI development could throw a spanner in the works.

Here's why investors might want to steer clear of SpaceX stock amid the uncertainty.

Image source: The Motley Fool.

SpaceX thinks AI is a $26.5 trillion opportunity

SpaceX operates three businesses:

1. Space transportation: SpaceX uses its Falcon 9 and Falcon Heavy reusable rockets to launch commercial payloads into orbit for businesses and government agencies.
2. Satellite connectivity: SpaceX has launched over 10,200 of its Starlink satellites into orbit, which beam internet access to over 12 million paying customers here on Earth.
3. AI: SpaceX acquired Elon Musk's xAI start-up earlier this year, which included state-of-the-art data centers like Colossus and Colossus II. The company uses this infrastructure to further develop the Grok models, but it also rents spare computing capacity to other businesses.

SpaceX values its addressable market in the space transportation industry at $370 billion, whereas it believes the satellite connectivity industry presents a $1.6 trillion opportunity. AI, however, could be a $26.5 trillion market across infrastructure, consumer subscriptions, and enterprise applications. Therefore, it's no surprise Musk and his team are focusing on capturing as much of that opportunity as possible.

There is a global shortage of the specialized data center chips and components necessary to run AI training and inference workloads, so developers are paying through the nose to lock in any computing capacity they can. Anthropic is expected to spend $1.25 billion per month to rent computing capacity from SpaceX's data centers through May 2029, so the agreement could be worth a whopping $45 billion overall.

SpaceX signed a separate deal to lease approximately $920 million in capacity to Google parent Alphabet from October 2026 to June 2029. It will also lease roughly $150 million worth of capacity per month to start-up Reflection AI through 2029.

These deals are coming so thick and fast that SpaceX chief financial officer Bret Johnsen thinks the company's AI business could achieve a $100 billion annual revenue run rate by the end of 2026. Moreover, Musk thinks the AI segment could propel SpaceX to $1 trillion in annual revenue as soon as 2030.

However, most customers can end their infrastructure agreements by providing 90 days' notice to SpaceX. If it turns out Anthropic won't need as much capacity due to its plan to pace its AI development, then there is a risk it will exit its contract with SpaceX much earlier than anticipated.

SpaceX stock could experience a sharp decline from here

SpaceX generated $7.8 billion in total revenue during the second quarter of 2026 (ended June 30), a whopping 92% increase from the year-ago period. Here's how it was broken down:

Data source: SpaceX.

As you can see, the connectivity segment still accounts for most of SpaceX's revenue, but the AI business is quickly catching up thanks to the company's growing portfolio of infrastructure deals.

That brings me to SpaceX's valuation, because investors are paying a hefty premium for the growth in the AI business right now. Based on the company's overall trailing 12-month revenue of $23 billion, its stock is trading at a price-to-sales (P/S) ratio of 87.3, making it 14 times as expensive as the Nasdaq-100 index, which has a P/S ratio of 6.1.

In other words, SpaceX appears to be heavily overvalued compared to a group of America's largest technology companies. Looking ahead, Wall Street believes SpaceX can grow its total revenue to $106.5 billion in 2027 (according to Yahoo Finance), placing its stock at a forward P/S ratio of 18.8. Therefore, it still seems expensive even if we look more than one year into the future.

But if large customers like Anthropic or Alphabet were to curb their AI spending to pace their development, SpaceX might not generate as much revenue next year as expected, so its stock could be even more expensive than it appears now.

SpaceX stock is already down 34% from its all-time high, but its valuation leaves significant room for further downside. As a result, investors might want to steer clear for the foreseeable future.

Anthony Di Pizio has no position in any of the stocks mentioned. The Motley Fool has positions in and recommends Alphabet. The Motley Fool has a disclosure policy.