V-Lab
S&P SmallCap 600 Index Spline-GARCH Volatility Analysis
Volatility prediction for Monday, September 14th, 2026
1 Day
15.06%
decreased by 0.28%
1 Week
15.57%
increased by 0.23%
1 Month
17.09%
increased by 1.75%
Analysis last updated: Saturday, September 12, 2026 at 12:55 AM UTC
News Impact Curve
How returns affect tomorrow's volatilityVolatility Forecast
How volatility evolves over timeParameter Estimates
Jan 1, 1990 to Sep 11, 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 19 trading days.
τ
Spline-GARCH Model
Tap to view equation
Time-varying baseline: volatility reverts to a slowly-shifting spline trend
| Param | Value | t-stat |
|---|---|---|
| ωconst | 0.7432 | 6.67*** |
| αARCH | 0.1027 | 10.47*** |
| βGARCH | 0.8615 | 74.05*** |
Spline Coefficients
K=5
| γ1 | 0.0229 | 2.50** |
| γ2 | -0.0301 | -2.13** |
| γ3 | -0.0023 | -0.22 |
| γ4 | 0.0260 | 2.72*** |
| γ5 | -0.0356 | -2.81*** |
0.964
Persistence19d
Half-lifeτ
Spline-GARCH Model
Tap to view equation
| Parameter | Value | t-statistic |
|---|---|---|
ω const Unconditional variance weight | 0.7432 | 6.67*** |
α ARCH Response to squared shocks | 0.1027 | 10.47*** |
β GARCH Volatility persistence | 0.8615 | 74.05*** |
Spline Coefficients
K=5
| γ1 | 0.0229 | 2.50** |
| γ2 | -0.0301 | -2.13** |
| γ3 | -0.0023 | -0.22 |
| γ4 | 0.0260 | 2.72*** |
| γ5 | -0.0356 | -2.81*** |
Persistence:
0.964
Half-life:
19 days
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