S&P MidCap 400 Index GAS-GARCH Student T Volatility Analysis
Volatility prediction for Thursday, November 5th, 2026
1 Day
13.61%
decreased by 0.09%
1 Week
13.77%
increased by 0.07%
1 Month
14.31%
increased by 0.61%
Analysis last updated: Thursday, November 5, 2026 at 12:17 AM UTC
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News Impact Curve
How returns affect tomorrow's volatilityVolatility Forecast
How volatility evolves over timeParameter Estimates
Jan 1, 1990 to Oct 30, 2026Model Insight
Volatility shocks decay with a half-life of 51 trading days, meaning a shock loses half its impact after approximately 51 days. Returns follow a Student-t distribution with v = 11.06 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 51-day half-lifev = 11.06 · fat tails
| Param | Value | t-stat |
|---|---|---|
| ωlong-run | 1.3577 | 2.83*** |
| αscore | 0.0884 | 9.29*** |
| βpersistence | 0.9866 | 179.31*** |
| νDF | 11.0556 | 1.11 |
0.987
Persistence51d
Half-life𝑓
GAS-GARCH-T Model
Tap to view equation
| Parameter | Value | t-statistic |
|---|---|---|
ω long-run Long-run variance given a price move | 1.3577 | 2.83*** |
α score Weight on the scaled score | 0.0884 | 9.29*** |
β persistence Volatility persistence | 0.9866 | 179.31*** |
ν DF Student-t tail thickness | 11.0556 | 1.11 |
Persistence:
0.987
Half-life:
51 days
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