Wilshire 5000 Total Market Index Zero Slope Spline-GARCH Volatility Analysis
Volatility prediction for Friday, July 10th, 2026
1 Day
13.20%
increased by 0.26%
1 Week
13.51%
increased by 0.57%
1 Month
14.42%
increased by 1.48%
Analysis last updated: Sunday, July 12, 2026 at 08:04 AM UTC
News Impact Curve
How returns affect tomorrow's volatilityVolatility Forecast
How volatility evolves over timeParameter Estimates
Jan 1, 1990 to Jan 2, 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 18 trading days.
τ
Zero Slope Spline-GARCH Model
Tap to view equation
| Parameter | Value | t-statistic |
|---|---|---|
ω const Unconditional variance weight | 1.0625 | 7.11*** |
α ARCH Response to squared shocks | 0.1071 | 9.82*** |
β GARCH Volatility persistence | 0.8556 | 66.26*** |
Spline Coefficients
K=8
| γ1 | 0.0496 | 1.67* |
| γ2 | -0.0108 | -0.23 |
| γ3 | -0.1272 | -3.86*** |
| γ4 | 0.1725 | 5.89*** |
| γ5 | -0.1589 | -6.02*** |
| γ6 | 0.1243 | 4.04*** |
| γ7 | -0.0556 | -1.72* |
| γ8 | -0.0003 | -0.01 |
Persistence:
0.963
Half-life:
18 days
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