V-Lab
Siemens AG Spline-GARCH Volatility Analysis
Volatility prediction for Friday, September 4th, 2026
1 Day
29.60%
decreased by 0.24%
1 Week
30.13%
increased by 0.29%
1 Month
31.79%
increased by 1.95%
Analysis last updated: Friday, September 4, 2026 at 06:51 PM UTC
News Impact Curve
How returns affect tomorrow's volatilityVolatility Forecast
How volatility evolves over timeParameter Estimates
Jan 2, 1990 to Aug 28, 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
Spline-GARCH Model
Tap to view equation
| Parameter | Value | t-statistic |
|---|---|---|
ω const Unconditional variance weight | 1.0091 | 5.92*** |
α ARCH Response to squared shocks | 0.0556 | 7.63*** |
β GARCH Volatility persistence | 0.9145 | 82.32*** |
Spline Coefficients
K=9
| γ1 | 0.0517 | 1.11 |
| γ2 | 0.0308 | 0.40 |
| γ3 | -0.2408 | -4.74*** |
| γ4 | 0.2930 | 7.22*** |
| γ5 | -0.2300 | -5.00*** |
| γ6 | 0.1424 | 3.18*** |
| γ7 | -0.0414 | -0.97 |
| γ8 | -0.0165 | -0.36 |
| γ9 | 0.0299 | 0.49 |
Persistence:
0.970
Half-life:
23 days
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