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Hong Kong Hang Seng Index GAS-GARCH Student T Volatility Analysis

Volatility prediction for Tuesday, October 20th, 2026

1 Day

16.36%

decreased by 0.36%

1 Week

16.49%

decreased by 0.23%

1 Month

16.96%

increased by 0.24%

Analysis last updated: Friday, October 16, 2026 at 09:10 AM UTC

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Date Range:

from

10/16/2024

to

10/16/2026

6M ·

1Y ·

2Y ·

5Y ·

10Y ·

All

graph of Hong Kong Hang Seng Index GAS-GARCH-T

News Impact Curve

How returns affect tomorrow's volatility

Volatility Forecast

How volatility evolves over time

Parameter Estimates

Jan 1, 1990 to Oct 16, 2026

Model Insight

With persistence 0.992, volatility shocks have a half-life of 90 trading days (~0.4 years), close to a unit root, so long-run forecasts are highly sensitive to this estimate. Returns follow a Student-t distribution with v = 7.07 degrees of freedom, capturing fatter tails than a normal distribution.

𝑓

GAS-GARCH-T Model

Tap to view equation

High persistence: persistence 0.992, shock half-life ~90 daysv = 7.07 · fat tails
ParamValuet-stat
ωconst2.1606
1.53
αARCH0.0556
9.87***
βGARCH0.9923
183.94***
νDF7.0736
1.47

0.992

Persistence

90d

Half-life
𝑓

GAS-GARCH-T Model

Tap to view equation

ParameterValuet-statistic
ω

const

Unconditional variance weight

2.1606
1.53
α

ARCH

Response to squared shocks

0.0556
9.87***
β

GARCH

Volatility persistence

0.9923
183.94***
ν

DF

Student-t tail thickness

7.0736
1.47

Persistence:

0.992

Half-life:

90 days