What this shows: the two ingredients of the current "AI bubble" debate, side by side. The top panel plots fixed investment in IT equipment — BEA Gross Private Domestic Investment: Nonresidential Equipment (FRED Y034RC1Q027SBEA, $bn, seasonally adjusted annual rate, quarterly). The red line is the raw series; the blue line is its 24-quarter moving average; the gray line is the S&P 500 (monthly closes, Yahoo Finance ^GSPC) on the left axis for context. The summary strip shows RSI(14) — Wilder's RSI computed on quarterly closes — where readings above 70 are historically rare and mark parabolic up-moves (the current reading is in the mid-90s).

Why it matters: the 1998–2000 surge in IT equipment investment (labelled "Y2K") and the 2007–08 run-up (labelled "2008") were both followed by sharp reversals. The 2023–2026 surge is the AI-capex analogue: investment has roughly doubled in three years, blowing past the dot-com peak in dollar terms.

Bottom panel: bank loans to non-depository financial institutions — the Fed H.8 weekly series (FRED LNFACBW027SBOG, $bn, not seasonally adjusted) — lending to hedge funds, private-credit funds and other non-bank financials. It has risen from ~$320bn in 2015 to ~$2.0 trillion today: the credit-side analogue of the AI capex boom.

Reading the chart: zoom in (scroll / shift+drag) to isolate individual episodes; the panels share one time axis. Data may be revised. Sources: chart data (JSON) · source series (CSV)