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V-Lab

S&P / ASX 200 Volatility Index GAS-GARCH Student T Volatility Analysis

Volatility prediction for Friday, August 21st, 2026

1 Day

73.24%

decreased by 1.97%

1 Week

78.52%

increased by 3.31%

1 Month

90.77%

increased by 15.56%

Analysis last updated: Friday, August 21, 2026 at 08:17 PM UTC

Date Range:

from

to

6M ·

1Y ·

2Y ·

5Y ·

10Y ·

All

graph of S&P / ASX 200 Volatility Index GAS-GARCH-T

News Impact Curve

How returns affect tomorrow's volatility

Volatility Forecast

How volatility evolves over time

Parameter Estimates

Jan 2, 2008 to Apr 4, 2025

Model Insight

Volatility shocks decay with a half-life of 10 trading days, meaning a shock loses half its impact after approximately 10 days. Returns follow a Student-t distribution with v = 4.52 degrees of freedom, capturing fatter tails than a normal distribution.

𝑓

GAS-GARCH-T Model

Tap to view equation

ParameterValuet-statistic
ω

const

Unconditional variance weight

45.6520
9.46***
α

ARCH

Response to squared shocks

0.0982
17.05***
β

GARCH

Volatility persistence

0.9299
119.33***
ν

DF

Student-t tail thickness

4.5157
6.13***

Persistence:

0.930

Half-life:

10 days