V-Lab
S&P 1000 Index GAS-GARCH Student T Volatility Analysis
Volatility prediction for Tuesday, September 22nd, 2026
1 Day
12.22%
decreased by 0.44%
1 Week
12.49%
decreased by 0.17%
1 Month
13.42%
increased by 0.76%
Analysis last updated: Monday, September 21, 2026 at 11:01 PM UTC
News Impact Curve
How returns affect tomorrow's volatilityVolatility Forecast
How volatility evolves over timeParameter Estimates
Dec 29, 1994 to Sep 18, 2026Model Insight
Volatility shocks decay with a half-life of 46 trading days, meaning a shock loses half its impact after approximately 46 days. Returns follow a Student-t distribution with v = 12.24 degrees of freedom, capturing fatter tails than a normal distribution.
𝑓
GAS-GARCH-T Model
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Shock decay: Shocks decay with a 46-day half-lifev = 12.24 · fat tails
| Param | Value | t-stat |
|---|---|---|
| ωconst | 1.4958 | 3.10*** |
| αARCH | 0.0915 | 8.50*** |
| βGARCH | 0.9851 | 173.28*** |
| νDF | 12.2359 | 0.94 |
0.985
Persistence46d
Half-life𝑓
GAS-GARCH-T Model
Tap to view equation
| Parameter | Value | t-statistic |
|---|---|---|
ω const Unconditional variance weight | 1.4958 | 3.10*** |
α ARCH Response to squared shocks | 0.0915 | 8.50*** |
β GARCH Volatility persistence | 0.9851 | 173.28*** |
ν DF Student-t tail thickness | 12.2359 | 0.94 |
Persistence:
0.985
Half-life:
46 days
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