V-Lab
S&P SmallCap 600 Index Zero Slope Spline-GARCH Volatility Analysis
Volatility prediction for Monday, September 14th, 2026
1 Day
14.94%
decreased by 0.28%
1 Week
15.43%
increased by 0.21%
1 Month
16.98%
increased by 1.76%
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 28 trading days.
τ
Zero Slope Spline-GARCH Model
Tap to view equation
Time-varying baseline: volatility reverts to a slowly-shifting spline trend
| Param | Value | t-stat |
|---|---|---|
| ωconst | 0.6323 | 10.26*** |
| αARCH | 0.1006 | 10.87*** |
| βGARCH | 0.8753 | 87.06*** |
Spline Coefficients
K=1
| γ1 | -0.0006 | -4.84*** |
0.976
Persistence28d
Half-lifeτ
Zero Slope Spline-GARCH Model
Tap to view equation
| Parameter | Value | t-statistic |
|---|---|---|
ω const Unconditional variance weight | 0.6323 | 10.26*** |
α ARCH Response to squared shocks | 0.1006 | 10.87*** |
β GARCH Volatility persistence | 0.8753 | 87.06*** |
Spline Coefficients
K=1
| γ1 | -0.0006 | -4.84*** |
Persistence:
0.976
Half-life:
28 days
Other S&P SmallCap 600 Index Analyses
Other Zero Slope Spline-GARCH Analyses on Equity Indices