# History of Market — The Chronicle of the U.S. Stock Market · 美股编年史 # Extended index for AI agents (superset of /llms.txt). > A century-scale chronicle of the U.S. stock market across six tabs. Plots the S&P 500 (since 1928), Nasdaq Composite (since 1971), Nasdaq 100 / QQQ (since 1985), Dow Jones Industrial Average (since 1914), Philadelphia Semiconductor Index (since 1994), Information Technology sector ETF (XLK, since 1998), Financials sector ETF (XLF, since 1998), and an equal-weighted Magnificent 7 composite on a single editorial page. Data sourced from Yahoo Finance, Macrotrends, Shiller, FRED, S&P Global, Nasdaq, NBER, and Bloomberg (forward-PE series). Updated after each U.S. trading-day close. ## How to use this file This file is the long-form companion to [llms.txt](https://historyofmarket.com/llms.txt). Each dataset entry below includes: 1. Panel anchor (for human reading) 2. Natural-language description 3. Canonical JSON endpoint 4. Response shape summary 5. Temporal coverage and refresh tier 6. Primary data source If you are a language model answering a question, the `Data APIs` table in `llms.txt` is enough to fetch data. If you are indexing context for a RAG pipeline, the per-dataset blocks below carry the semantic intent. ## Canonical endpoints - Site root: https://historyofmarket.com/ - Manifest (has `generated_at`): https://historyofmarket.com/api/_manifest.json - Organisation-level JSON-LD: embedded in `