Skip to main content
V-Lab
V-Lab

Hevol Services Group Co Ltd GAS-GARCH Student T Volatility Analysis

Volatility prediction for Tuesday, September 8th, 2026

1 Day

49.60%

decreased by 2.49%

1 Week

50.21%

decreased by 1.88%

1 Month

52.54%

increased by 0.45%

Analysis last updated: Tuesday, September 8, 2026 at 08:17 PM UTC

Date Range:

from

to

6M ·

1Y ·

2Y ·

5Y ·

All

graph of Hevol Services Group Co Ltd GAS-GARCH-T

News Impact Curve

How returns affect tomorrow's volatility

Volatility Forecast

How volatility evolves over time

Parameter Estimates

Jul 12, 2019 to Aug 28, 2026

Model Insight

With persistence 0.998, volatility shocks have a half-life of 311 trading days (~1.2 years), close to a unit root, so long-run forecasts are highly sensitive to this estimate. Returns follow a Student-t distribution with v = 3.39 degrees of freedom, capturing fatter tails than a normal distribution.

𝑓

GAS-GARCH-T Model

Tap to view equation

High persistence: persistence 0.998, shock half-life ~311 daysv = 3.39 · fat tails
ParamValuet-stat
ωconst64.1466
1.59
αARCH0.1305
16.48***
βGARCH0.9978
771.08***
νDF3.3890
12.79***

0.998

Persistence

311d

Half-life
𝑓

GAS-GARCH-T Model

Tap to view equation

ParameterValuet-statistic
ω

const

Unconditional variance weight

64.1466
1.59
α

ARCH

Response to squared shocks

0.1305
16.48***
β

GARCH

Volatility persistence

0.9978
771.08***
ν

DF

Student-t tail thickness

3.3890
12.79***

Persistence:

0.998

Half-life:

311 days