S&P 500 · Log YoY — Fourteen Crossings of Zero: A Century of Structural Regimes
Macro Regimes — Segmenting nearly a century of market cycles via log YoY momentum, isolating fourteen structural bull and bear regime shifts.
The plate
Latest Snapshot
- Latest close
- 7,722.722026-10-02
- Observations
- 24,806
- Sample
- 1927-12-30 – 2026-10-02
Log year-over-year price change provides a smoothed measure of 12-month momentum, where positive values denote bull expansions and negative values denote bear contractions. Across nearly a century, the series crossed the zero line just fourteen times, marking the fundamental turning points between economic cycles.
What this page answers
This static page is built to answer searches for S&P 500 · Log YoY. It summarizes the live dataset behind the Fourteen Crossings of Zero: A Century of Structural Regimes panel and links to the full interactive chart.
Log year-over-year price change provides a smoothed measure of 12-month momentum, where positive values denote bull expansions and negative values denote bear contractions. Across nearly a century, the series crossed the zero line just fourteen times, marking the fundamental turning points between economic cycles. The data is refreshed by the History of Market pipeline and published as a stable JSON endpoint for research, citation, and AI-agent use.
Data & Source
GET /api/sp500/price.json — Canonical dataset endpoint.
Exchange closing prices · Company filings · Robert Shiller · FRED · NBER.
FAQ
Where does this data come from?
History of Market combines public market and macro datasets — exchange closing prices, company filings, Robert Shiller, FRED, NBER, and the UBS Global Investment Returns Yearbook (Dimson–Marsh–Staunton). The exact endpoint for this panel is linked below.
How often is it updated?
Daily-tier datasets refresh after the U.S. market close, with a broader weekly refresh on Sunday. The timestamp shown on this page comes from the JSON payload.
Can I use the data?
Yes, for research and education with attribution to History of Market. Upstream data sources retain their own terms.