Methodology
KOSPI Fear & Greed Index
The KOSPI Fear & Greed Index (KFG) expresses Korean market sentiment as a single number between 0 and 100 — 0 for fear, 100 for greed, the same direction as the CNN index.
Korea has no official fear and greed index. The CNN version draws on options volume, junk-bond spreads and other inputs specific to US markets. This index is a proxy that moves that structure onto three axes reproducible from KOSPI prices alone. It does not measure sentiment directly; it infers it from the traces sentiment leaves in price.
Because it uses only price, the same formula can be carried back to 1998. The formula and weights are published in full below.
Inputs and weights
Each input is converted to a 0–100 score and combined with the weights below. If an input is unavailable, it is excluded and the remaining weights are renormalised to sum to 100%.
| Components | Weight |
|---|---|
Momentum — KOSPI 125-day MA deviation How far KOSPI trades from its own 125-day moving average. It measures position against the intermediate trend, with ±12% mapping to 100 and 0 respectively. | 40% |
Position within the 52-week range Where the current level sits between the 52-week low and high, expressed as 0–100. Near the high it approaches 100; near the low it approaches 0. | 30% |
Volatility (inverse of its one-year percentile) The percentile of 20-day realised volatility within the trailing year, subtracted from 100. Calmer markets score higher. The reason for using a percentile rather than an absolute level is explained in the methodology below. | 30% |
Score mapping
125-day MA deviation → score
A deviation of 0% maps to 50, +12% to 100 and −12% to 0, linearly and clipped at both ends. The ±12% range reflects KOSPI's typical swing.
52-week position → score
(price − 52-week low) ÷ (52-week high − 52-week low) × 100, used directly. This is the only input with no further transformation.
Volatility → score
20-day realised volatility is annualised, its percentile within the trailing year is taken, and that percentile is subtracted from 100. The most volatile day of the past year scores 0; the calmest scores 100.
Data and updates
Only the daily closes of KOSPI (^KS11) are used. No survey or options data enters the calculation, which is what makes the whole record computable on identical terms.
Volatility enters as a percentile rather than an absolute level for a reason. What counts as normal volatility differs by era: a calm day in 2008 and a calm day in 2017 are numerically far apart, so an absolute threshold would tilt entire historical stretches in one direction. A percentile against the trailing year keeps the meaning stable as regimes change.
The index updates once daily after the close is final, and a published value is never revised.
1998-01-30 ~ 2026-07-21 · 7,016
How the values are distributed
The values are not evenly spread around the midpoint. Across the full record the mean is about 57 and the median about 61; greed territory (55 and above) covers roughly 57% of days and fear territory (below 45) roughly 33%. This is a property of the formula: during long advances, prices spend more time above their moving average and in the upper part of the 52-week range. Rather than treating 50 as neutral, read the percentile shown alongside the value.
Limitations
- Sentiment is not measured directly. There is no survey and no flow data — only price. Sentiment that has not yet shown up in price will not appear here.
- One index only. KOSPI alone is used, so KOSDAQ and individual sectors are not represented.
- Not comparable to the CNN index. The inputs differ, so an identical number does not describe an identical state.
- A low reading is not a buy signal. In 2008, extreme fear persisted for months while prices continued to fall.
- This is not an official index. It is not produced by an exchange or index provider and does not underlie any financial product.
Frequently asked questions
- How does this differ from the CNN Fear & Greed Index?
- Different market and different construction. CNN covers US equities using seven inputs including options volume, junk-bond demand and safe-haven preference. This index uses the three inputs obtainable from KOSPI prices. The direction is the same (0 fear, 100 greed) but an identical number does not mean an identical state.
- Did it actually read low during past crises?
- Yes. October 2008 averaged 1.4, March 2020 averaged 9.5 and October 2000 averaged 5.1, while January 2021 averaged 80.0. That shows the index describes those periods well after the fact — not that it announced them in advance.
- Why does the history start in 1998?
- The 52-week range and the volatility percentile each need at least 252 trading days of prices. KOSPI data is available from late 1996, so the first date satisfying that requirement is January 1998.
Download the full history (kfg.json) · 1998-01-30 ~ 2026-07-21 · CC BY 4.0