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V-Lab

SEI Select Small CAP ETF GAS-GARCH Student T Volatility Analysis

Volatility prediction for Wednesday, September 9th, 2026

1 Day

18.99%

decreased by 0.12%

1 Week

19.22%

increased by 0.11%

1 Month

19.81%

increased by 0.70%

Analysis last updated: Tuesday, September 8, 2026 at 10:28 PM UTC

Date Range:

from

to

6M ·

1Y ·

All

graph of SEI Select Small CAP ETF GAS-GARCH-T

News Impact Curve

How returns affect tomorrow's volatility

Volatility Forecast

How volatility evolves over time

Parameter Estimates

Oct 10, 2024 to Sep 4, 2026

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 = 5.56 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 10-day half-lifev = 5.56 · fat tails
ParamValuet-stat
ωconst1.7122
0.84
αARCH0.0358
0.63
βGARCH0.9343
14.02***
νDF5.5603
0.11

0.934

Persistence

10d

Half-life
𝑓

GAS-GARCH-T Model

Tap to view equation

ParameterValuet-statistic
ω

const

Unconditional variance weight

1.7122
0.84
α

ARCH

Response to squared shocks

0.0358
0.63
β

GARCH

Volatility persistence

0.9343
14.02***
ν

DF

Student-t tail thickness

5.5603
0.11

Persistence:

0.934

Half-life:

10 days