Principal Focused Blue Chip ETF Zero Slope Spline-GARCH Volatility Analysis
Volatility prediction for Tuesday, July 21st, 2026
1 Day
13.17%
decreased by 2.42%
1 Week
12.23%
decreased by 3.36%
1 Month
11.32%
decreased by 4.27%
Analysis last updated: Tuesday, July 21, 2026 at 02:15 AM UTC
News Impact Curve
How returns affect tomorrow's volatilityVolatility Forecast
How volatility evolves over timeParameter Estimates
Jul 13, 2023 to Jul 17, 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 2 trading days.
τ
Zero Slope Spline-GARCH Model
Tap to view equation
| Parameter | Value | t-statistic |
|---|---|---|
ω const Unconditional variance weight | 0.3447 | 4.17*** |
α ARCH Response to squared shocks | 0.1377 | 2.66*** |
β GARCH Volatility persistence | 0.5630 | 3.09*** |
Spline Coefficients
K=8
| γ1 | -7.6674 | -1.12 |
| γ2 | 11.0849 | 1.05 |
| γ3 | -5.0511 | -0.66 |
| γ4 | 9.5377 | 1.23 |
| γ5 | -23.3539 | -2.84*** |
| γ6 | 42.4826 | 5.47*** |
| γ7 | -61.3931 | -7.64*** |
| γ8 | 49.8504 | 7.94*** |
Persistence:
0.701
Half-life:
2 days
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