Bloomberg: Anthropic is SpaceX’s largest customer, bringing in 34.5% of its third-quarter revenue

An unnamed “Customer B” in the filing

The concentration-of-risk note in the 10-Q that SpaceX (Space Exploration Technologies Corp.) filed with the Securities and Exchange Commission on Oct. 22, covering the quarter ended Sept. 30, lists two large customers without naming them. “Customer B” accounted for 34.5% of consolidated third-quarter revenue and 24.2% of revenue for the first nine months of the year. In the same periods of 2025, its share was less than 10%. According to the filing, revenue from Customer B relates only to the SI (Super Intelligence) segment. “Customer A,” whose revenue relates to all three segments, accounted for 16.6% in the third quarter, down from 23.9% a year earlier.

SI is the unit SpaceX formerly called its AI segment. According to the filing, SpaceX completed its acquisition of X.AI Holdings, the parent of xAI, on Feb. 2 and closed its merger with Cursor on Aug. 14; Cursor is included in SI. Third-quarter revenue rose 161% from a year earlier, from $5.58 billion to $14.58 billion. Of that, $7.56 billion came from SI, compared with $813 million a year earlier. Connectivity brought in $5.25 billion and Space $1.77 billion. The company ended the quarter with net income of $4.4 billion.

The filing gives no dollar amount for Customer B. A 34.5% share works out to about $5 billion, or roughly two-thirds of SI’s quarterly revenue.

The identification rests on one Bloomberg source

Bloomberg reported on Oct. 29, citing a single person familiar with the matter, that Customer B is Anthropic. SpaceX’s filing does not name Anthropic, and neither company has confirmed it. According to TNW, Anthropic declined to comment and SpaceX did not respond to Bloomberg. According to Investing.com, that puts Anthropic ahead of the U.S. federal government, previously SpaceX’s largest customer.

The size of the deal

Anthropic’s IPO filing (S-1), submitted to the SEC on Oct. 26, shows that its computing agreements with SpaceX.AI LLC, a SpaceX subsidiary, could total up to $120.5 billion over terms extending into 2029. That figure is a ceiling, not a guaranteed total. According to TeslaNorth, the filing says the capacity is powered by Nvidia GPUs and lists Vera Rubin systems among the hardware. Once all contracted capacity is delivered, payments reach about $3.1 billion a month, or about $37 billion a year. Anthropic expects full delivery in December 2026; fees differ while capacity ramps up.

The agreements have grown since they were first disclosed. On May 20, Bloomberg Law reported, based on SpaceX’s IPO paperwork, that Anthropic would pay SpaceX nearly $45 billion over three years for computing for Claude. That original deal called for $1.25 billion a month through May 2029, with capacity ramping up in May and June 2026 at a reduced fee. The S-1’s $120.5 billion ceiling and roughly $3.1 billion monthly rate are the current figures.