CoreWeave's 67 Percent — When One Customer Is Your Revenue

The Concentration That Climbed

CoreWeave's fiscal 2025 Form 10-K — filed March 2, 2026, the kind of filing a person prints if the person has decided to stop pretending the screen is cheaper — said Microsoft accounted for approximately 67 percent of total revenue. In fiscal 2024 the same customer was 62 percent, sitting at the top of a top-two pair that together were 77 percent. In fiscal 2023 the top three were about 73 percent, and the Microsoft-shaped line in later retellings sat near 35 percent.

I am using the 10-K's nouns. Customer A, Customer B, Customer C in the concentration footnote; Microsoft by name in the risk factors when the year made the name unavoidable. No customer other than Microsoft was 10 percent or more of fiscal 2025 revenue. That is not diversification. That is a silence where Customer B used to be.

Revenue itself did the cartoon: about $229 million in fiscal 2023 to about $5.1 billion in fiscal 2025, if you walk the series the aggregators walk off the XBRL. Growth that steep with a customer that concentrated is a weather. The weather has a ticker now. CoreWeave listed in March 2025. The listing did not make the 67 percent a stranger.

Nestor wrote 35 → 62 → 67 and then he wrote one name. He said one name is a risk factor that has already happened. I said the risk factor is still written as a future. He said futures are how 10-Ks stay polite.

The Supplier Who Is Also the Stockholder Who Is Also the Residual Buyer

On September 9, 2025, CoreWeave and NVIDIA entered a new order form under a master services agreement dated April 10, 2023. The order had an initial value of $6.3 billion. It let CoreWeave sell reserved capacity to its own customers and gave NVIDIA the residual — the hours nobody else took — through April 13, 2032, subject to delivery and availability and the usual termination language about breach and bankruptcy. The 8-K said, in a sentence I have read too many times, that in addition to the MSA, NVIDIA supplies the company with GPUs and is a stockholder.

On January 23, 2026, NVIDIA bought 22,935,780 shares of CoreWeave Class A common stock at $87.20 per share for $2 billion in cash, in a private placement under Section 4(a)(2). The 8-K is dated around that week. The joint release talked about more than five gigawatts of AI factories by 2030. The cash sat in CoreWeave's financing activities, net of issuance costs, and in NVIDIA's pile of purchases of non-marketable securities.

I want you to hold the triangle without becoming a poster. NVIDIA sells chips to CoreWeave. NVIDIA owns CoreWeave stock. NVIDIA is obligated, on the residual, to buy CoreWeave's unsold hours. CoreWeave's largest customer is Microsoft. Microsoft's largest AI lab relationship is OpenAI. OpenAI also has an order form with CoreWeave — May 2025 MSA, September 2025 order up to about $6.5 billion through May 31, 2031, in the retellings that walk the 10-K. Meta has been in the building since a December 2023 MSA, with more order forms landing in 2026. Jane Street put a number on the table that coverage put near $6 billion.

Diversification, in this zip code, is more names in the same weather.

Debt Is the Other Customer

A neocloud that grows like that does not grow on cash from strangers. It grows on debt that believes the backlog, and a backlog that believes the chips, and chips that believe the residual buyer. Coverage in 2026 put contracted backlog in the tens of billions and then, depending on the week, past $60 billion of remaining performance obligations and toward numbers that made a person check the date. The debt service is a chapter I will not write as a thriller. I will write it as a washer: it walks when it spins.

I sat with Nestor while he read a blog that said 168 percent revenue growth could not cover debt service. He said blogs are gift shops. I said the 10-K is the museum. He said then stay in the museum. I am staying. The museum says concentration and capex and a customer who is also a competitor building their own rooms.

The Meeting Called Anchor Tenant

I sat, while I still had a badge, in a meeting whose title was anchor tenant economics. The slide had a logo and a percentage. The percentage was not 67. It was a forecast that wanted to be 40. Forecasts that want to be 40 are how you keep a board in a chair. I asked what happens if the anchor builds their own. Someone said that is why we have the residual. Someone else said the residual is a different logo. I said the different logo sells the chips. The table did the laugh that means we will not put that in the notes.

Afterward I stood by a window that did not open and wrote residual on a napkin. I still have the napkin. I do not have the forecast.

What 67 Percent Means in a Kitchen

Hattie has one employer. If the district fails she does not have a residual NVIDIA. She has unemployment and a checkbook. Bess has one classroom. If the classroom fails she has a union and a night. CoreWeave has a 10-K that can say 67 percent and still be worth a multiple, because the multiple believes the weather will hold.

I am not short the ticker. I am telling you the ticker is a concentration with a listing. Listings do not diversify a kitchen. They diversify a shareholder register.

The IPO That Did Not Diversify the Kitchen

March 2025. A ticker. A price. A story about a neocloud that had been a crypto miner in a previous costume and was now an AI factory in a press release. NVIDIA anchored coverage of the offering in the retellings — a $250 million order at $40 a share sits in some of those retellings like a relic. I will not swear to the relic if the 424B sits in a drawer I have not opened this week. I will swear to the 10-K: 67 percent Microsoft in fiscal 2025; 62 percent in fiscal 2024; a top-three concentration in fiscal 2023 that later retellings put Microsoft near 35 percent. The listing added holders. It did not add strangers to the revenue line.

Hattie asked what an IPO is if the customer is still one name. I said it is a shareholder register that got louder. She said loud is not a customer. I said that is the chapter.

Meta, OpenAI, Jane Street — Same Weather, More Chairs

The 10-K and the later 8-Ks added chairs. Meta: a master services agreement from December 2023 and additional order forms, including 2026 paper that coverage put in the tens of billions, some of it starting later. OpenAI: May 2025 MSA; September 2025 order form up to about $6.5 billion through May 31, 2031. Jane Street: a number coverage put near $6 billion in the 2026 weather. Anthropic: a multi-year agreement the company was willing to announce and not always willing to price.

Q1 2026 commentary said the top two customers were about 65 percent of revenue, which is a decline from a one-name 67 percent only if you enjoy fractions. I enjoy fractions when Bess teaches them. I do not enjoy them when they are used as a personality.

Nestor wrote chairs and then weather and then he drew a line that was not a circle because he refuses circles. I stole the chairs. I left the line.

The 8-K Sentence I Keep in a Wallet

"In addition to the MSA, NVIDIA supplies the Company with NVIDIA GPUs and is a stockholder of the Company." I photocopied that sentence and cut it out and put it behind a credit-union receipt, which is a sentimental habit I will not defend. The sentence is the triangle without a consultant. Supplier. Residual buyer. Stockholder. The 8-K dated the residual order September 9, 2025, $6.3 billion initial value, through April 13, 2032. The 8-K dated the $2 billion January 23, 2026. I do not need a podcast. I need a wallet.

Felix asked to see the slip. I showed him. He said it looked like a parlay. I said a parlay is a bet. He said a caddie knows a parlay. I said then do not take the cart. He took Rourke's cart. I walked.

Capex That Is a Multiple of the Year

The aggregators who walk CoreWeave's XBRL will tell you capex can run at a multiple of revenue in a build year — two times, in some of the fiscal-2025 retellings — and that remaining performance obligations later sat in the tens of billions, $60.7 billion in one walk, higher in later weeks. I will not freeze a backlog that moves like Oracle's. I will freeze the shape: you borrow to build, you build to host, you host for a name, the name is also building their own, the chip vendor eats leftovers, the leftovers are still a P&L, the debt service is a washer that walks.

A blog said 168 percent growth could not cover the service. Nestor said blogs are gift shops. I said gift shops sometimes sell maps. He said then steal the shape and leave the adjective. I stole the shape.

A Crypto Costume, Briefly, Because the 10-K Remembers

CoreWeave's earlier life, in the rooms that walk the S-1, includes a crypto-mining costume. I am not going to do a origin-story montage. I am going to say a company can change its weather and keep its appetite for power and for someone else's chips. The appetite is the through-line. The ticker is a costume change. Costume changes do not reset a concentration. They reset a deck.

Hattie asked what crypto was. I said it was a prior religion. She said she does not do prior. She does Tuesdays. I said Tuesdays are a better religion. She said do not put that on a tote.

The Competitor-Customer

Microsoft is the customer and also the company building rooms that will not need a neocloud when the rooms are ready. The 10-K can say that in a risk factor and still be a growth story. Growth stories are allowed to have risk factors. Risk factors are allowed to be the plot. I sat in a meeting where we called this "complementary until it isn't." Until it isn't is a residual order. The residual order has a date: April 13, 2032. Dates are more honest than complementary.

Gideon said complementarity is strategy. I said strategy is a vest. He said I should get a vest. I said I have a checkbook on a counter. He said that is not a strategy. I said that is the point.

The Stock That Learned a Hill

Coverage in late August 2026 put CoreWeave near $90, down about half from a June 2025 high that those rooms put near $184, with a backlog number that had grown and a debt number that had not become a personality. I will not freeze a price. I will freeze the shape: a listing can teach a concentration to go downhill in public. Downhill is a weather. Weather is not a fraud. Weather is why a 10-K writes 67 percent as a future and a tape writes it as a mood.

Felix said he "got out." I said I would not comment on a caddie's book. He said caddies have books. I said then he is already more honest than a run rate. He asked for a five. I gave him a five. Fives are the only marks I make on that course.

Forty-Three Sites Is a Map I Will Not Draw

Coverage that walks CoreWeave's operational footnotes will give you site counts and megawatts — forty-three sites, hundreds of megawatts active, gigawatts contracted, in the 2026 retellings. I will not draw the map. Maps are a gift shop. I will say a concentration can be geographically various and still be one customer. Geography is not diversification if the invoice is one name. Invoices are kitchens. Kitchens do not care about your site list.

Hattie asked if forty-three was a lot of buildings. I said it was a lot of buildings with one weather. She said weather is what she opens a window for. I said this book is not the window book. She said good. She does not like to share a window.

The MSA That Became Material

The April 10, 2023, NVIDIA master services agreement was already in the house. The September 9, 2025, order form made the MSA material within the meaning of Item 1.01, the 8-K said, because it was no longer immaterial in amount or significance. That sentence is a company admitting a parent. Parents become material when the number gets a billion. I photocopied no longer immaterial and put it behind the other slip. My wallet is a 10-K. Nestor hates my wallet. Termination: thirty days' written notice of breach; bankruptcy weather not dismissed in ninety days. Ordinary. Ordinary is how a residual can still be a cliff. Cliffs are Chapter 9. I am waving.

Item 1.01 Is a Parent Going Public

No longer immaterial in amount or significance. I have written sentences like that for rooms that wanted to stay children. Item 1.01 is how a residual becomes a citizen. Citizens have 8-Ks. Children have decks. CoreWeave's NVIDIA MSA graduated. Graduation is not diversification. Graduation is a parent on a form.

Felix asked what Item 1.01 was. I said a confession with a number. He said then it is a tip. I said it is a tip the tape can read. He asked for a five. I had already given him a five. I gave him nothing. Nothing is a fold Cora would respect.

The Wallet's Table of Contents

Behind the credit-union receipt: the 8-K sentence about GPUs and stockholder. Behind that: no longer immaterial. Behind that: a five I have not given Felix. The wallet is a museum. Museums have ropes. I will not add a site map. Site maps are forty-three pins. Pins are a gift shop. The wallet stays dull.

Hank asked if I wanted a new wallet. I said no. He said the old one is a weather. I said weather is the point. He cut a key. The key was a tool. I did not buy a wallet.

The Five I Have Not Given

There is a five in the wallet I have not given Felix. I am leaving it there so the wallet does not become a tip jar. Tip jars are Ida's room. Felix has a Roth and a parlay and a grip he dries in rain. He does not need my five to be a character. He needs the bag to be lighter. I carry my own. Carrying is the only Item 1.01 I will file on myself.

Lighter

Felix needs the bag lighter. I carry my own. I am ending on lighter, because 67 percent is a heavy name and a listing does not lift it. Lifting would be strangers. Strangers did not arrive. Chairs arrived. Chairs share weather. Weather is heavy. I left the five in the wallet. The wallet stays dull.