V-Lab
Russell 1000 Growth Index Spline-GARCH Volatility Analysis
Volatility prediction for Friday, September 11th, 2026
1 Day
16.93%
increased by 0.18%
1 Week
17.47%
increased by 0.72%
1 Month
19.26%
increased by 2.51%
Analysis last updated: Friday, September 11, 2026 at 09:04 AM UTC
News Impact Curve
How returns affect tomorrow's volatilityVolatility Forecast
How volatility evolves over timeParameter Estimates
May 12, 2000 to Sep 4, 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 38 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 | 1.2885 | 7.22*** |
| αARCH | 0.1060 | 10.45*** |
| βGARCH | 0.8758 | 81.25*** |
Spline Coefficients
K=1
| γ1 | 0.0047 | 3.53*** |
0.982
Persistence38d
Half-lifeτ
Spline-GARCH Model
Tap to view equation
| Parameter | Value | t-statistic |
|---|---|---|
ω const Unconditional variance weight | 1.2885 | 7.22*** |
α ARCH Response to squared shocks | 0.1060 | 10.45*** |
β GARCH Volatility persistence | 0.8758 | 81.25*** |
Spline Coefficients
K=1
| γ1 | 0.0047 | 3.53*** |
Persistence:
0.982
Half-life:
38 days
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