Mention SpaceX stock and most people picture rockets. But these days more than half of the money SpaceX makes comes from AI: it builds huge data centers and rents the computers inside them to companies that make AI. And one of those renters, a company that has not been named, paid 34.5% of everything SpaceX sold last quarter.
You may already own a little of this. SpaceX joined the Nasdaq-100 in July, so anyone with money in a Nasdaq-100 fund now holds a piece of it. When it joined, reports put its weight at under 1% of the index, so the piece is small. I hold SpaceX this way myself, through a Nasdaq-100 fund, and that is why the unnamed renter caught my eye.
A rocket company that now rents out computers
| Quarter ended Sep 30, 2026 | Sales |
|---|---|
| AI: renting out computers, its own Grok chatbot, and the Cursor coding app it bought in August | $7.6B |
| Starlink internet and other connections | $5.2B |
| Rockets and space | $1.8B |
| Total | $14.6B (+161% from a year earlier) |
Rockets are now the smallest of the three. SpaceX takes the cash from launches and Starlink and spends it on AI data centers, the same rush to build that has helped chip makers and equipment makers such as Vertiv.
On the earnings call, Elon Musk said SpaceX wants to use about half of its computers itself and rent the other half out at roughly the going market price, rather than locking in long contracts. Prices set that way rise quickly when demand is strong and fall just as quickly when it weakens. So I wanted to know who is paying them.
One customer makes up a third of sales
SpaceX does not name its biggest renter, but its quarterly report says how much it pays: 34.5% of all sales, all on the AI side. By my math that comes to about $5B in one quarter. That one customer paid SpaceX 2.9 times as much as the whole rocket business brought in.
A year ago, this company was not even a tenth of sales. A second big customer adds 16.6%, so two companies now make up more than half of SpaceX’s sales.
So who is it? The report does not say, and I will not guess. Here is what it does say. The money comes from deals to rent out AI computing, which SpaceX calls infrastructure contracts and cloud services agreements.
The report also lists SpaceX’s dealings with companies tied to Musk or its directors: buying Tesla batteries, leasing equipment from a director’s fund, and a stake in The Boring Company. It calls everything else small. Sales of billions a quarter do not appear on that list.
What if that customer leaves? By my math, last quarter’s sales would have been about $9.5B instead of $14.6B. The AI side would shrink to about $2.5B, because this one customer is 67% of it. And the data centers built for that demand would still be standing.
Signed contracts give some protection. Customers have already signed contracts for $63B of services SpaceX has not provided yet, and about 67% of it should be delivered within a year. So the money cannot vanish overnight. But the report does not say how much of that is the big renter’s, and the backlog leaves out services billed as they are used, so rent charged at the going price may not be in it at all.
Is spending more than its sales a problem?
It can work, but only if two things go right. SpaceX spent more on data centers and chips last quarter than it made in sales.
And it plans to spend $35B to $40B this quarter. The company says new computers pay for themselves in under a year at today’s rental prices.
First, rental prices have to stay near today’s level. The AI business made its first operating profit, the money left after running costs: $431M, only 5.7% of what the AI side brought in. That profit already counts $1.2B of shares given to Cursor’s staff after the August purchase, a cost SpaceX expects to keep adding for years. With so little left over, a small drop in rental prices would wipe it out.
Second, the big renter has to keep renting at the same pace. It alone is most of the AI side, and the payback math assumes the computers stay busy.
Is SpaceX stock expensive?
SpaceX began trading in June. It shot up, sank after its first report, and now sits just above where it started.
On Oct 28, 2026 it closed about 8% above its listing price. Measured against profit, though, the price is high, and that profit needs a closer look.
Last quarter’s net profit was $4.4B, well above the $2.8B left from running the businesses. Part of the gap did not come from selling anything. The Boring Company, a tunnel firm Musk controls, raised money at a higher value, so SpaceX booked a $561M paper gain on its stake. It also booked a gain on the Bitcoin it holds (the report does not give that amount alone) and a $390M tax benefit.
If SpaceX earned last quarter’s profit in every quarter for a year, the share price would be about 103.7 times that year’s profit. Leave out the Boring gain and, by my math, it is about 117.9 times. And over the first nine months of 2026 together, SpaceX lost $413M, so there is no full year of profit to price it on yet. Buyers of SpaceX are paying for what it might earn later, not for what it earns now.
What to watch in the next report
So it comes down to one unnamed renter and two numbers to read side by side: that customer’s share of sales, and how much of each AI dollar SpaceX keeps.
- Share up, and SpaceX keeps more of each dollar: the big customer is adding profit, not just sales.
- Share up, but SpaceX still keeps only a few cents: it may be holding on to that customer by cutting prices.
- Share down: the signed backlog keeps some sales coming for a while, but the data centers built for that customer still have to be paid for.
My guess for the next report, from past filing dates, is between Jan 20 and Feb 4, 2027.
A year from now, will SpaceX's biggest customer pay a bigger share?
How each language voted
Resolves: SpaceX's report for the quarter ending September 2027 · Reader opinions, not investment advice.
Sources
- SpaceX third quarter 2026 results (SEC Form 8-K, exhibit)
- SpaceX quarterly report for Q3 2026 (SEC Form 10-Q), customer concentration, backlog, related parties, other income, IPO
- SpaceX Q3 2026 earnings call transcript (StockAnalysis)
- SpaceX GPU finance lease commitment with an Apollo-managed entity (SEC Form 8-K)
- Nasdaq, SpaceX's fast entry into the Nasdaq-100 (July 2026)