SOX / SPX · SOX / XLK · XLK / SPX — Who's leading, who's lagging
Relative strength — SOX vs. S&P 500 and vs. XLK — who's leading.
Three rebased ratios, indexed to 100 at year-end 1999. Semis vs the broad market, semis vs the broader tech sector, and tech vs the broad market. Click any legend entry to toggle a line; zoom in to read each leadership regime.
What this page answers
This static page is built to answer searches for SOX / SPX · SOX / XLK · XLK / SPX. It summarizes the live dataset behind the Who's leading, who's lagging panel and links to the full interactive chart.
Three rebased ratios, indexed to 100 at year-end 1999. Semis vs the broad market, semis vs the broader tech sector, and tech vs the broad market. Click any legend entry to toggle a line; zoom in to read each leadership regime. The data is refreshed by the History of Market pipeline and published as a stable JSON endpoint for research, citation, and AI-agent use.
The plate
Latest Snapshot
- Updated
- 2026-08-14
Data & Source
GET /api/semi/ratios.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.