Elon Musk's surprise Anthropic deal allows him to accomplish two things at once: turn unused compute into revenue before an expected SpaceX IPO next month — and stick it to his archrival, Sam Altman.

Why it matters: Musk went from calling Anthropic "evil" to doing business with it in three months, showing how quickly competition can give way to strategic necessity in the AI race.

The big picture: The deal helps Anthropic address one of its most pressing problems — a severe compute deficit. The company saw "80x growth per year in revenue and usage" for the first quarter of 2026, CEO Dario Amodei said at a developer conference Wednesday, when it only planned for 10x.

That demand spike gave the AI lab "difficulties with compute," Amodei added, referencing recent usage limits that have frustrated customers.
Enter SpaceX, which will provide the AI lab with the entire capacity of its Colossus 1 data center, amounting to more than 300 megawatts of new capacity (over 220,000 Nvidia GPUs) within the month.
xAI, Musk's AI lab that SpaceX acquired, will continue to run off Colossus 2, a separate supercomputer.
"As part of this agreement, Anthropic also expressed interest in partnering to develop multiple gigawatts of orbital AI compute capacity," SpaceX said in a blog post.

The intrigue: The deal comes as Musk is embroiled in a lawsuit against OpenAI, the AI lab he co-founded that also happens to be Anthropic's biggest competitor.

"Elon's enemy is Sam. Dario's enemy is Sam. Enemy of my enemy is a compute partner," Ben Pouladian, who does tech market research, wrote on X.
Musk publicly attacked Anthropic on X in February, calling it "misanthropic" in response to the AI lab announcing its $380 billion post-money valuation. (Anthropic is now expected to be valued closer to $900 billion.)
Now, Musk says he "was impressed" after meeting with senior Anthropic leaders last week.

Follow the money: It's not just about personalities or competition. The deal makes financial sense for both parties, especially as Musk's xAI has a very different demand curve than Anthropic.

Musk has a history of over-investing in infrastructure relative to product demand, PitchBook's Harrison Rolfes tells Axios via email. (In 2024, OpenAI scooped up capacity originally intended for Musk.)
"xAI's Colossus 1 ended up with capacity that Grok's user base never grew into," Rolfes said.
By leasing that capacity to Anthropic, Musk turns an idle, expensive asset into a high-margin revenue stream for SpaceX, just in time for its June S-1 filing. That will allow him to avoid a multi-billion dollar write-down on unused chip capacity before the company is expected to go public.
Instead, SpaceX can go public with Anthropic as a customer.

Yes, but: Musk wouldn't have lent this spare capacity to a competing AI lab if he had the same demand problem Amodei describes having at Anthropic.

The company is only utilizing 11% of the potential of its massive chips stash, per The Information, though it's unclear how much of that is driven by lack of demand, low utilization or a combination.

The bottom line: Anthropic has the cash Musk needs to shore up his company's balance sheet before it goes public, and Musk has the compute Anthropic needs to meet user demand and continue its exponential revenue growth.