Most investors think of "AI stocks" as a single category. But the AI supply chain is a deep, layered structure where each layer has different cycle dynamics, margin profiles, and bottleneck risks. Silicon (Layer 1) is capital-intensive with long lead times. Memory (Layer 2) is highly cyclical with pricing power swings. Compute (Layer 4) is where NVIDIA dominates but custom ASICs are emerging. Understanding which layer you're investing in determines your risk profile.
The Functional Index tracks all six layers independently. When Layer 1 (Silicon) outperforms Layer 4 (Compute), it signals that the supply chain is building ahead of demand — a healthy leading indicator. When Layer 4 outperforms alone, it suggests demand concentration without broad supply chain confirmation.
Layer 1 — Silicon: ASML, TSMC, Applied Materials, Lam Research, BESI. Lithography, fabrication, packaging. The physical foundation. Longest lead times, highest capital intensity.
Layer 2 — Memory: Micron, SK Hynix, Samsung Memory. HBM, DDR5, storage. Most cyclical layer. HBM pricing is the key signal for AI demand health.
Layer 3 — Networking: Broadcom, Arista, Marvell, Coherent. Interconnects, switches, optical. The connective tissue between compute nodes. Increasingly bottlenecked as cluster sizes grow.
Layer 4 — Compute: NVIDIA, AMD, Intel, Google TPU, AWS Trainium. GPUs, custom ASICs, inference accelerators. The most visible layer but not the only one that matters.
Layer 5 — Data Platforms: Snowflake, Datadog, Confluent, Elastic. Cloud infrastructure, databases, observability. The software layer agents and AI applications run on.
Layer 6 — End Markets: Tesla, Apple, Meta, enterprise deployers. Where AI meets the real world. Demand-side indicator for the entire stack.
The 6-Layer Model is the organizing principle behind everything Closelook publishes. The Functional Index is built on it, the research dossiers are organized by it, and portfolio allocation decisions reference it. Understanding which layer you're exposed to is the first step in AI infrastructure investing.
Functional Index — All 6 Layers →AI Chip Buildout Dossier →Functional Index — Why It's Better →
