V-Lab
Siemens AG Zero Slope Spline-GARCH Volatility Analysis
Volatility prediction for Tuesday, August 25th, 2026
1 Day
27.48%
decreased by 0.61%
1 Week
27.86%
decreased by 0.23%
1 Month
29.08%
increased by 0.99%
Analysis last updated: Tuesday, August 25, 2026 at 06:38 PM UTC
News Impact Curve
How returns affect tomorrow's volatilityVolatility Forecast
How volatility evolves over timeParameter Estimates
Jan 2, 1990 to Aug 21, 2026Model Insight
This model fits a time-varying baseline (a spline), so volatility mean-reverts toward a slowly-shifting long-run level rather than a constant. Short-run deviations decay with a half-life of 23 trading days.
τ
Zero Slope Spline-GARCH Model
Tap to view equation
| Parameter | Value | t-statistic |
|---|---|---|
ω const Unconditional variance weight | 1.0257 | 6.03*** |
α ARCH Response to squared shocks | 0.0553 | 7.61*** |
β GARCH Volatility persistence | 0.9154 | 83.68*** |
Spline Coefficients
K=9
| γ1 | 0.0582 | 1.24 |
| γ2 | 0.0185 | 0.24 |
| γ3 | -0.2279 | -4.46*** |
| γ4 | 0.2780 | 6.75*** |
| γ5 | -0.2152 | -4.61*** |
| γ6 | 0.1325 | 2.94*** |
| γ7 | -0.0404 | -0.96 |
| γ8 | -0.0051 | -0.12 |
| γ9 | -0.0069 | -0.22 |
Persistence:
0.971
Half-life:
23 days
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