Skip to main content
V-Lab
V-Lab

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

Volatility prediction for Friday, September 4th, 2026

1 Day

61.37%

decreased by 3.07%

1 Week

61.19%

decreased by 3.25%

1 Month

60.47%

decreased by 3.97%

Analysis last updated: Friday, September 4, 2026 at 11:27 PM UTC

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 Aug 27, 2026

Model Insight

With persistence 0.996, volatility shocks have a half-life of 182 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 ~182 daysv = 6.27 · fat tails
ParamValuet-stat
ωconst3.3115
1.40
αARCH0.0610
13.67***
βGARCH0.9962
408.61***
νDF6.2709
2.88***

0.996

Persistence

182d

Half-life
𝑓

GAS-GARCH-T Model

Tap to view equation

ParameterValuet-statistic
ω

const

Unconditional variance weight

3.3115
1.40
α

ARCH

Response to squared shocks

0.0610
13.67***
β

GARCH

Volatility persistence

0.9962
408.61***
ν

DF

Student-t tail thickness

6.2709
2.88***

Persistence:

0.996

Half-life:

182 days