Skip to main content
V-Lab
V-Lab

Korea Stock Exchange KOSPI 200 Index GAS-GARCH Student T Volatility Analysis

Volatility prediction for Monday, September 28th, 2026

1 Day

43.82%

decreased by 1.62%

1 Week

43.72%

decreased by 1.72%

1 Month

43.32%

decreased by 2.12%

Analysis last updated: Friday, September 25, 2026 at 08:56 PM UTC

Press Delete or Backspace to remove this series.
Date Range:

from

to

6M ·

1Y ·

2Y ·

5Y ·

10Y ·

All

graph of Korea Stock Exchange KOSPI 200 Index GAS-GARCH-T

News Impact Curve

How returns affect tomorrow's volatility

Volatility Forecast

How volatility evolves over time

Parameter Estimates

Jan 3, 1990 to Sep 23, 2026

Model Insight

With persistence 0.996, volatility shocks have a half-life of 171 trading days (~0.7 years), close to a unit root, so long-run forecasts are highly sensitive to this estimate. Returns follow a Student-t distribution with v = 6.27 degrees of freedom, capturing fatter tails than a normal distribution.

𝑓

GAS-GARCH-T Model

Tap to view equation

High persistence: persistence 0.996, shock half-life ~171 daysv = 6.27 · fat tails
ParamValuet-stat
ωconst3.2428
1.38
αARCH0.0620
13.34***
βGARCH0.9959
373.43***
νDF6.2666
2.81***

0.996

Persistence

171d

Half-life
𝑓

GAS-GARCH-T Model

Tap to view equation

ParameterValuet-statistic
ω

const

Unconditional variance weight

3.2428
1.38
α

ARCH

Response to squared shocks

0.0620
13.34***
β

GARCH

Volatility persistence

0.9959
373.43***
ν

DF

Student-t tail thickness

6.2666
2.81***

Persistence:

0.996

Half-life:

171 days