State Street Consumer Staples Select Sector SPDR ETF Zero Slope Spline-GARCH Volatility Analysis
Volatility prediction for Tuesday, July 21st, 2026
1 Day
18.89%
decreased by 1.17%
1 Week
18.66%
decreased by 1.40%
1 Month
17.89%
decreased by 2.17%
Analysis last updated: Monday, July 20, 2026 at 09:52 PM UTC
News Impact Curve
How returns affect tomorrow's volatilityVolatility Forecast
How volatility evolves over timeParameter Estimates
Dec 22, 1998 to Jul 17, 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 20 trading days.
τ
Zero Slope Spline-GARCH Model
Tap to view equation
| Parameter | Value | t-statistic |
|---|---|---|
ω const Unconditional variance weight | 1.8206 | 9.42*** |
α ARCH Response to squared shocks | 0.1087 | 9.64*** |
β GARCH Volatility persistence | 0.8564 | 62.02*** |
Spline Coefficients
K=2
| γ1 | 0.0112 | 6.13*** |
| γ2 | -0.0132 | -5.74*** |
Persistence:
0.965
Half-life:
20 days
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