V-Lab
Siemens AG GAS-GARCH Student T Volatility Analysis
Volatility prediction for Tuesday, September 15th, 2026
1 Day
28.91%
1 Week
28.93%
1 Month
29.01%
Analysis last updated: Wednesday, September 16, 2026 at 06:30 PM UTC
News Impact Curve
How returns affect tomorrow's volatilityVolatility Forecast
How volatility evolves over timeParameter Estimates
Jan 2, 1990 to Sep 14, 2026Model Insight
With persistence 0.997, volatility shocks have a half-life of 209 trading days (~0.8 years), close to a unit root, so long-run forecasts are highly sensitive to this estimate. Returns follow a Student-t distribution with v = 6.06 degrees of freedom, capturing fatter tails than a normal distribution.
GAS-GARCH-T Model
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| Param | Value | t-stat |
|---|---|---|
| ωconst | 4.0167 | 1.25 |
| αARCH | 0.0531 | 15.50*** |
| βGARCH | 0.9967 | 393.17*** |
| νDF | 6.0606 | 3.28*** |
0.997
Persistence209d
Half-lifeGAS-GARCH-T Model
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| Parameter | Value | t-statistic |
|---|---|---|
ω const Unconditional variance weight | 4.0167 | 1.25 |
α ARCH Response to squared shocks | 0.0531 | 15.50*** |
β GARCH Volatility persistence | 0.9967 | 393.17*** |
ν DF Student-t tail thickness | 6.0606 | 3.28*** |
Persistence:
0.997
Half-life:
209 days
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