AI Stocks vs Dot-com Bubble: CAPE at 38, Concentration Above 2000 Levels, but Companies Are Actually Profitable
The AI rally looks like the dot-com bubble. The companies do not.
- TL;DR:
- The Shiller CAPE ratio stands at 38-40, second highest in 155 years behind only the dot-com peak of 44.19.
- S&P 500 top-10 concentration exceeds dot-com levels by nearly 50%.
- Unlike dot-com predecessors, AI companies are massively profitable.
- The resolution depends on whether hyperscaler capex generates returns justifying the investment.
The Numbers Tell a Story
The Shiller cyclically adjusted price-to-earnings ratio for the S&P 500 is approximately 38 to 40, higher than at any time in 155 years of recorded data, except March 2000, when it reached 44.19.
- The ten largest companies in the S&P 500 now account for 36% to 40% of the index’s total market capitalisation, nearly 50% above the dot-com peak concentration.
- 57% of institutional investors identify an AI valuation crash as the single greatest risk to markets.
- Jeremy Grantham has stated there is "slim to none" chance the current AI rally does not end in a bust.
Structural Parallels to Dot-Com Bubble
The parallels between the current AI equity rally and the dot-com bubble are mechanical:
- Market concentration: Exceeded dot-com levels by a wide margin.
- Dominant companies: Nasdaq-100 performance dominated by a handful of AI-focused companies.
- Hyperscaler capex: Microsoft, Google, Amazon, and Meta investing $660 billion to $690 billion in 2026, the largest corporate investment programme in history outside of wartime.
- Job cuts and infrastructure shift: Meta and Microsoft cutting up to 23,000 jobs while funding record capex.
Bearish Outlook
Bank of America’s Savita Subramanian targets S&P 500 at 7,100 with a bear case of 5,500. The Motley Fool identifies four bubble conditions:
- Retail investor euphoria
- Speculative capital concentration
- Decoupling of valuations from fundamentals
- A compelling narrative that discourages scepticism
All four are present.
OpenAI’s Valuation: $852 Billion for a Non-Profit
OpenAI’s $852 billion valuation prices a company that has never earned a profit at roughly double.