The AI Infrastructure Stack
Overview  /  Tier I Demand
Layer 02

Foundation Models

The labs that train the models the rest of the stack runs on.

What this layer does

This is the layer of capital-burning research labs. A frontier training run costs hundreds of millions to billions of dollars in compute alone, before headcount or data. The output is a model that other layers either resell (cloud APIs), wrap (applications), or compete with (open-weight challengers).

The economics here are extreme: revenue scales fast, but compute cost scales with usage. Gross margins depend on how cheaply the lab can serve inference — which depends on the model architecture, the GPUs it’s tuned for, and any custom silicon (Anthropic on Trainium, Google on TPU).

There are no pure-play public model labs. Exposure comes through the partners and infrastructure each lab depends on.

Sub-categories

Analysis coming soon — will cover: training cost trajectories, the open vs. closed debate, post-training as the new moat, why every frontier lab is bolted to a hyperscaler, and how to get public-market exposure to lab winners.