State Street Utilities Select Sector SPDR ETF Spline-GARCH Volatility Analysis
Volatility prediction for Thursday, October 15th, 2026
1 Day
17.56%
decreased by 0.54%
1 Week
17.93%
decreased by 0.17%
1 Month
19.16%
increased by 1.06%
Analysis last updated: Wednesday, October 14, 2026 at 10:39 PM UTC
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News Impact Curve
How returns affect tomorrow's volatilityVolatility Forecast
How volatility evolves over timeParameter Estimates
Dec 22, 1998 to Oct 9, 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 30 trading days.
τ
Spline-GARCH Model
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Time-varying baseline: volatility reverts to a slowly-shifting spline trend
| Param | Value | t-stat |
|---|---|---|
| ωconst | 1.2407 | 10.08*** |
| αARCH | 0.0867 | 8.62*** |
| βGARCH | 0.8901 | 82.34*** |
Spline Coefficients
K=1
| γ1 | 0.0040 | 4.45*** |
0.977
Persistence30d
Half-lifeτ
Spline-GARCH Model
Tap to view equation
| Parameter | Value | t-statistic |
|---|---|---|
ω const Unconditional variance weight | 1.2407 | 10.08*** |
α ARCH Response to squared shocks | 0.0867 | 8.62*** |
β GARCH Volatility persistence | 0.8901 | 82.34*** |
Spline Coefficients
K=1
| γ1 | 0.0040 | 4.45*** |
Persistence:
0.977
Half-life:
30 days
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