V-Lab
S&P SmallCap 600 Index GAS-GARCH Student T Volatility Analysis
Volatility prediction for Monday, August 17th, 2026
1 Day
13.83%
decreased by 0.42%
1 Week
13.97%
decreased by 0.28%
1 Month
14.51%
increased by 0.26%
Analysis last updated: Friday, August 14, 2026 at 11:05 PM UTC
News Impact Curve
How returns affect tomorrow's volatilityVolatility Forecast
How volatility evolves over timeParameter Estimates
Jan 1, 1990 to Aug 14, 2026Model Insight
With persistence 0.992, volatility shocks have a half-life of 82 trading days (~0.3 years), close to a unit root, so long-run forecasts are highly sensitive to this estimate. Returns follow a Student-t distribution with v = 10.55 degrees of freedom, capturing fatter tails than a normal distribution.
𝑓
GAS-GARCH-T Model
Tap to view equation
| Parameter | Value | t-statistic |
|---|---|---|
ω const Unconditional variance weight | 1.7197 | 8.40*** |
α ARCH Response to squared shocks | 0.0839 | 40.85*** |
β GARCH Volatility persistence | 0.9916 | 875.94*** |
ν DF Student-t tail thickness | 10.5462 | 5.25*** |
Persistence:
0.992
Half-life:
82 days
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