If you don’t believe me and @edzitron maybe you will believe Claude and Gemini. Whether you do or n...
Gary Marcus(@GaryMarcus) · 人工智能
If you don’t believe me and @edzitron maybe you will believe Claude and Gemini. Whether you do or not, the outcome will be the same. Luke Hutchison @LH I had Claude and Gemini work together on analyzing the size of the AI bubble (including the circular-funding circus), the exposure of retirement savings to AI-linked stocks, and a comparison to the size of the 2008 subprime mortgage crisis -- then had Claude cross-check everything and write a combined report. Claude's executive summary: -- The AI bubble by the numbers (Nov 6, 2026) SIZE • AI-linked stocks: ~$30T, ~40% of the US stock market • Value above long-run trend: ~$12-14T (central estimate; range $2-22T) • Funded AI debt: ~$1-2T, plus ~$4-5T of purchase and lease commitments BUBBLE INDICATORS • S&P 500 CAPE: 41 (dot-com peak: 44) • US market cap/GDP: ~229%, near its 240% all-time record (dot-com peak: 144%) • Top 10 stocks = 40% of the S&P 500 (16% in 2016) • AI revenue covers at most 20% of the $1T+ spent on AI infrastructure in 2026 • Big Tech capex ($1T in 2026) exceeds operating cash flow ($804B); hyperscaler free cash flow projected negative by early 2027 • Circular financing: IMF counts $300B equity + $650B debt flowing between AI firms, tied to $1.4T of revenue commitments back to the investors • Suppliers guaranteeing their customers' debt: ~$260B of explicit backstops (Broadcom alone up to $43B) • Profits flattered: $160B of $285B in Q2 profit at 5 megacaps came from marking up private AI stakes; longer server depreciation lives add billions per year • Credit stress: Nvidia CDS hit a record in July; neocloud borrowing now costs ~10% • Nov 5: Nasdaq -5.5% into correction; chip stocks -12%, worst day since March 2020 RETIREMENT SAVINGS EXPOSURE • Total US retirement assets: $51.2T (IRAs $19.9T, 401(k)/DC plans $15.0T, pensions $13.6T, annuities $2.7T) • Invested in AI-linked stocks: ~$10T (range $6-16T), or 12-32% of all retirement assets • Retirement accounts and pensions hold ~1/3 of all US stocks • A