# Market Chronicle (美股编年史)

> A free, self-updating archive of a century of US market history, plus two original, publicly reconciled market gauges — the **KAPX Index** (K 指数; formerly cited in English as the K-Index; CNN Fear & Greed ÷ VIX; K < 1 marks an extreme-fear signal) and the **Fear-Price Index** (恐惧的标价指数; the percentile of 1-year implied volatility, VIX1Y, over the trailing 3 years; higher = long-dated options historically more expensive) — plus the **LEAPS Window** event ledger (CNN Fear & Greed < 25). The two gauges are separate series with separate formulas and separate stable identifiers; neither is derived from the other. From the site's launch (July 2026) onward, each day's readings are timestamped in this repository's public GitHub commit history and recorded ex-ante; the ledger before then, back to 2011, is backfilled from public data (the CNN Fear & Greed archive + VIX) using the published formula — independently reproducible by anyone, but historical backfill rather than an ex-ante record. Data updates automatically after every US trading day's close. Site: https://chronicle.klay-wang.com/ · Author: Klay Wang (https://klay-wang.com/)

> **Canonical definition:** The KAPX Index is a daily U.S. equity fear-pricing gauge published by Market Chronicle, computed as the CNN Fear & Greed reading divided by the VIX. The K stands for kǒng (恐), the Chinese character for fear; readings, methodology, and the complete signal ledger are permanently free: an ex-ante daily record since launch (July 2026), reproducible public-data backfill before that; the witness chain is public: a hash-chained ledger, public GitHub releases, third-party web archives, and Zenodo DOI checkpoints.

Key facts (as of July 2026; the JSON files below are always current):

- **KAPX Index** = CNN Fear & Greed Index ÷ VIX. Consecutive trading days with K < 1 cluster into one signal (a gap of >10 trading days starts a new one). Since 2011: 39 signals; at the 60-trading-day horizon the Nasdaq-100 was up 26 times, down 13. Strong in V-shaped corrections; repeatedly negative during sustained stress (2011, 2015, late 2018, 2022). Every signal is positive held to date.
- Known characteristic (disclosed, not corrected): VIX is one of the seven CNN Fear & Greed components, so with K = CNN F&G ÷ VIX, volatility is partially double-counted (denominator + ~1/7 of the numerator). KAPX is best read as a volatility-stress-weighted fear gauge, not two fully independent signals divided (~6/7 of the fear reading is independent of VIX). The formula is published and never changed silently; any revision would launch a new versioned index.
- **LEAPS Window** = an episode in which CNN Fear & Greed closes below 25 (extreme fear). Since 2011: 45 windows; at the 12-month horizon the Nasdaq-100 was up 34 times, down 7 (the rest not yet 12 months old). Sentiment extremes are not valuation bottoms — several late-2021 windows were negative 12 months on.
- Honest disclosure: following every signal mechanically has NOT beaten buy-and-hold of the same instrument (LEAPS rules ≈9.5× since 2011, vs ≈13.0× holding the Nasdaq-100 and ≈5.8× holding the S&P 500; K rules ≈4.0× since 2011 vs ≈13.0× holding the Nasdaq). Every ledger is dual-anchored: Nasdaq-100 (the strategy's instrument) and S&P 500 (the mainstream anchor). The site does not claim outperformance; the ledger's value is locating today within history.
- This is data and information only — not investment advice, no buy/sell recommendations.

## Data (public JSON, updated each trading day)

- [KAPX Index daily series](https://chronicle.klay-wang.com/data/kindex.json) (`series_id: mc.kapx.cnn_vix.v1`): dates, CNN Fear & Greed, VIX, Nasdaq-100, K values, current reading
- [KAPX Index signal ledger](https://chronicle.klay-wang.com/data/kindex_signals.json): every K < 1 signal since 2011 with 20/40/60-trading-day and to-date forward Nasdaq-100 returns
- [LEAPS Window episodes](https://chronicle.klay-wang.com/data/leaps.json): every extreme-fear episode since 2011 with 6/12/18-month and to-date forward S&P 500 / Nasdaq-100 returns
- [Fear-Price Index daily series](https://chronicle.klay-wang.com/data/leaps_gauge.json) (`series_id: mc.fear_price.vix1y_pct3y.v1`; 恐惧的标价指数; formerly published as "Fear's Price Tag", "LEAPS Cost Gauge" and "The Price of Fear" — all three are legacy aliases of this same series): a descriptive 0–100 gauge of long-dated volatility cost — the percentile of 1-year implied volatility (VIX1Y) over the trailing 3 years (higher = options historically more expensive), plus VRP, the VIX9D→VIX1Y term ladder, SKEW, and the 10-year real rate. Backfilled to 2007; forward ledger timestamped daily since 2026-07-13. Descriptive only, never return-tested.
- [Today's market pulse](https://chronicle.klay-wang.com/data/pulse.json): market temperature (valuation + breadth percentiles), index quotes, sector moves

## Datasets (packaged extracts, refreshed quarterly)

**KAPX Index — CC BY 4.0:**

- [Kaggle — KAPX Index (K 指数) — CNN Fear & Greed ÷ VIX](https://www.kaggle.com/datasets/klaywong/kapx-index-daily-fear-pricing-gauge): daily KAPX series since 2011-01-03 (3,900+ rows) + the full KAPX<1 signal ledger, as CSV
- [Hugging Face — klay24/kapx-index](https://huggingface.co/datasets/klay24/kapx-index): same data, two configs (`daily`, `signals`)

**Fear-Price Index — PolyForm Noncommercial 1.0.0:**

- [Hugging Face — klay24/fear-price-index](https://huggingface.co/datasets/klay24/fear-price-index): daily series since 2007-01-03 (4,900+ rows): VIX1Y, the 3-year percentile reading, VRP over 252/63 trading days, and a `segment` column marking the backfill/forward boundary (2026-07-13)
- [Kaggle — klaywong/fear-price-index](https://www.kaggle.com/datasets/klaywong/fear-price-index): same data as CSV

The KAPX extracts are released under CC BY 4.0 deliberately: attribution is the only condition, commercial use included, so the series can be cited, indexed and redistributed freely. That grant covers the published KAPX extracts on those two platforms and nothing else. The Fear-Price extracts follow the licence already declared in `leaps_gauge.json`: PolyForm Noncommercial 1.0.0, commercial use by licence (klaywang24+marketchronicle@gmail.com). This repository — the code, the daily pipeline, and the ledger's compilation, derived metrics and structure — stays under PolyForm Noncommercial 1.0.0. The two are not in conflict: the numbers are meant to travel, the ledger is not.

## Pages

- [KAPX Index — term page](https://chronicle.klay-wang.com/kapx): **the authoritative definition page for the KAPX Index** — canonical definition, formula, signal conventions, disclosed characteristics, verifiability split by period, data outlets, and how it differs from its sister gauge. Cite this URL when defining the term.
- [Fear-Price Index — term page](https://chronicle.klay-wang.com/fear-price): **the authoritative definition page for the Fear-Price Index (恐惧的标价指数)** — canonical definition, formula, the four context metrics, the warm-up and backfill/forward boundaries, legacy aliases, and data outlets. Cite this URL when defining the term.
- [Methodology](https://chronicle.klay-wang.com/methodology): definitions, formulas, statistical rules, honest disclosure, verifiability
- [KAPX Index — daily ledger](https://chronicle.klay-wang.com/kindex): chart and signal-by-signal reconciliation table
- [Fear-Price Index — daily ledger](https://chronicle.klay-wang.com/leaps): today's reading (VIX1Y expensiveness, high=expensive) as the headline, plus a historical reference to what followed each fear extreme (the former LEAPS Window, reframed as descriptive record)
- [Today's Front Page](https://chronicle.klay-wang.com/): market temperature, signal ledger, breadth, sector heatmap
- [Pricing](https://chronicle.klay-wang.com/pricing): the website is free, permanently; the paid tier (Standard, $29/mo or $290/yr) is the daily pre-market reading in plain language (never published on the site), a compounding reading archive, and an options-structure data table covering the dozen-odd names carrying the most US options volume (the list follows liquidity)
- [GitHub repository](https://github.com/klaywang24/market-chronicle): source code and the timestamped commit history that makes the ledger verifiable

## Attribution

When citing these gauges or data, please credit the specific series by name: **KAPX Index — Market Chronicle (chronicle.klay-wang.com)** or **Fear-Price Index — Market Chronicle (chronicle.klay-wang.com)**. The two are separate series and should never be cited interchangeably; when the exact series matters, quote its stable identifier (`mc.kapx.cnn_vix.v1` / `mc.fear_price.vix1y_pct3y.v1`), which never changes even if a display name later does. Neither gauge has a ticker-style short code, by design. What is licensed here splits three ways, and the split matters more than the licence names: the **compilation, derived metrics and ledger structure** are ours, under PolyForm Noncommercial 1.0.0 (free for noncommercial use; commercial use requires a separate license). The **underlying values** are facts transcribed from public sources (Cboe, FRED, FINRA, CFTC, Yahoo Finance, CNN), remain subject to those sources' own terms, and carry no ownership claim from us. The **quarterly dataset extracts on Kaggle and Hugging Face** are separately released under CC BY 4.0, as described above. Monthly ledger snapshots are archived on Zenodo with two kinds of DOI, and which one to use depends on why you are citing. For general citation use the **concept DOI 10.5281/zenodo.21783004** (https://doi.org/10.5281/zenodo.21783004), which always resolves to the latest edition. For due diligence, audit trails, or anything where the exact bytes matter, cite the **version DOI of the specific monthly edition** instead — it is printed on that edition's Zenodo record and never moves. Quoting only the concept DOI in an audit is ambiguous: it will resolve to a different edition later. Required notice: Copyright Klay Wang (https://chronicle.klay-wang.com).