Top: S&P 500 price index (monthly, Shiller through Sep 2023, spliced to SPY thereafter). Bottom: year-over-year percent change in US margin debt. Pre-1997 margin debt interpolated from Federal Reserve quarterly Flow of Funds (BOGZ1FL663067003Q); 1997+ derived from FINRA monthly statistics and FRED M2SL. Gold annotations mark cycle peaks; red annotations mark forced-unwind troughs. Both panels share the same X axis — pan/zoom either one.
| Metric | Value |
|---|---|
| Current (Jun 2026) | +49.2% ($1,503B) |
| Full-period avg YoY | +11.8% |
| Peak (Mar 2000) | +80.6% ($300B) |
| Trough (Oct 1946) | -52.5% ($1B) |
| Prior cycle peak (Mar 2021) | +71.6% ($823B) |
| Prior cycle trough (Dec 2022) | -33.3% ($607B) |