V-Lab
NASDAQ Composite Index Zero Slope Spline-GARCH Volatility Analysis
Volatility prediction for Thursday, August 20th, 2026
1 Day
18.51%
decreased by 0.86%
1 Week
18.81%
decreased by 0.56%
1 Month
19.72%
increased by 0.35%
Analysis last updated: Thursday, August 20, 2026 at 12:03 AM UTC
News Impact Curve
How returns affect tomorrow's volatilityVolatility Forecast
How volatility evolves over timeParameter Estimates
Jan 1, 1990 to Aug 14, 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 | 0.7506 | 7.35*** |
α ARCH Response to squared shocks | 0.0998 | 10.31*** |
β GARCH Volatility persistence | 0.8633 | 71.90*** |
Spline Coefficients
K=8
| γ1 | 0.0095 | 0.33 |
| γ2 | 0.0479 | 1.07 |
| γ3 | -0.1730 | -5.52*** |
| γ4 | 0.2052 | 7.27*** |
| γ5 | -0.1481 | -5.86*** |
| γ6 | 0.1058 | 3.81*** |
| γ7 | -0.0608 | -2.18** |
| γ8 | 0.0093 | 0.46 |
Persistence:
0.963
Half-life:
18 days
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