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V-Lab

Appian Corp GAS-GARCH Student T Volatility Analysis

Volatility prediction for Tuesday, September 22nd, 2026

1 Day

67.13%

decreased by 0.55%

1 Week

67.10%

decreased by 0.58%

1 Month

66.99%

decreased by 0.69%

Analysis last updated: Monday, September 21, 2026 at 09:19 PM UTC

Date Range:

from

to

6M ·

1Y ·

2Y ·

5Y ·

All

graph of Appian Corp GAS-GARCH-T

News Impact Curve

How returns affect tomorrow's volatility

Volatility Forecast

How volatility evolves over time

Parameter Estimates

May 25, 2017 to Sep 18, 2026

Model Insight

Volatility shocks decay with a half-life of 39 trading days, meaning a shock loses half its impact after approximately 39 days. Returns follow a Student-t distribution with v = 4.79 degrees of freedom, capturing fatter tails than a normal distribution.

𝑓

GAS-GARCH-T Model

Tap to view equation

Shock decay: Shocks decay with a 39-day half-lifev = 4.79 · fat tails
ParamValuet-stat
ωconst17.4190
0.87
αARCH0.0533
3.55***
βGARCH0.9825
44.46***
νDF4.7893
0.99

0.982

Persistence

39d

Half-life
𝑓

GAS-GARCH-T Model

Tap to view equation

ParameterValuet-statistic
ω

const

Unconditional variance weight

17.4190
0.87
α

ARCH

Response to squared shocks

0.0533
3.55***
β

GARCH

Volatility persistence

0.9825
44.46***
ν

DF

Student-t tail thickness

4.7893
0.99

Persistence:

0.982

Half-life:

39 days