Elon Musk’s companies love to work together. Now, we have a bit more insight into how much money is moving between them.
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On Wednesday, SpaceX filed its 277-page S-1, a document that peels back the curtain on the combined space-and-AI company’s spending.
The filing showed that SpaceX (and its recently acquired fellow Musk company, xAI) bought hundreds of millions of dollars’ worth of products from Tesla. Purchases included $697 million in Tesla Megapack products across 2024 and 2025, plus $131 million in Cybertrucks in 2025. The rocket company also bought an additional $34 million in Megapacks between January and March of this year.
The purchases were listed as “related party transactions.”
The filing also described other ties between the companies — including work on voice-assistance features in Tesla vehicles, plans for a combined-use chip factory, and Tesla ad purchases on X.
“SpaceX and Tesla developed the early foundation of a strong and constructive partnership through a series of limited but successful commercial engagements,” SpaceX wrote in the filing.
Seth Goldstein, an equity strategist at Morningstar who covers Tesla, said the related-party spending is “a little unique” to Tesla and SpaceX, but that the purchases themselves do not strike him as unusual.
“A company like SpaceX purchasing a large amount of work trucks and batteries for energy storage is not unusual and would be necessary for its business,” he told Business Insider. “If what SpaceX is buying from Tesla or vice versa is necessary for its operations, then it makes sense.”
Goldstein did say one element may raise investor eyebrows: SpaceX reported buying the Cybertrucks “at manufacturer’s suggested retail price.” He said most companies receive a discount when buying products in bulk.
That wording also offers a rare window into how many Cybertrucks may have gone to one of Musk’s own companies.
Tesla sold 20,237 Cybertrucks in 2025, according to Kelley Blue Book. SpaceX did not reveal which trims it purchased, but based on Tesla’s posted MSRP for the Cybertruck, the $131 million purchase would imply roughly 1,183 to 1,813 vehicles.
That means SpaceX’s Cybertruck purchase could have represented about 6% to 9% of Tesla’s Cybertruck sales last year.
SpaceX didn’t respond to a request for comment from Business Insider.
