NASDAQ Composite Index Zero Slope Spline-GARCH Volatility Analysis
Volatility prediction for Thursday, July 16th, 2026
1 Day
19.13%
decreased by 0.66%
1 Week
19.37%
decreased by 0.42%
1 Month
20.09%
increased by 0.30%
Analysis last updated: Thursday, July 16, 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 Jul 10, 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 | 0.7487 | 7.35*** |
α ARCH Response to squared shocks | 0.0999 | 10.29*** |
β GARCH Volatility persistence | 0.8630 | 71.56*** |
Spline Coefficients
K=8
| γ1 | 0.0082 | 0.28 |
| γ2 | 0.0511 | 1.14 |
| γ3 | -0.1769 | -5.65*** |
| γ4 | 0.2083 | 7.45*** |
| γ5 | -0.1498 | -5.95*** |
| γ6 | 0.1060 | 3.82*** |
| γ7 | -0.0596 | -2.14** |
| γ8 | 0.0079 | 0.39 |
Persistence:
0.963
Half-life:
18 days
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