V-Lab
Ishares Core Equity ETF PTF Zero Slope Spline-GARCH Volatility Analysis
Volatility prediction for Monday, September 21st, 2026
1 Day
11.26%
decreased by 0.57%
1 Week
11.58%
decreased by 0.25%
1 Month
12.46%
increased by 0.63%
Analysis last updated: Saturday, September 19, 2026 at 09:18 AM UTC
News Impact Curve
How returns affect tomorrow's volatilityVolatility Forecast
How volatility evolves over timeParameter Estimates
Aug 13, 2019 to Sep 18, 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 13 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 | 1.4606 | 2.64*** |
| αARCH | 0.1276 | 5.01*** |
| βGARCH | 0.8218 | 30.86*** |
Spline Coefficients
K=2
| γ1 | 0.1232 | 1.29 |
| γ2 | -0.1445 | -1.26 |
0.949
Persistence13d
Half-lifeτ
Zero Slope Spline-GARCH Model
Tap to view equation
| Parameter | Value | t-statistic |
|---|---|---|
ω const Unconditional variance weight | 1.4606 | 2.64*** |
α ARCH Response to squared shocks | 0.1276 | 5.01*** |
β GARCH Volatility persistence | 0.8218 | 30.86*** |
Spline Coefficients
K=2
| γ1 | 0.1232 | 1.29 |
| γ2 | -0.1445 | -1.26 |
Persistence:
0.949
Half-life:
13 days
Other Ishares Core Equity ETF PTF Analyses
Other Zero Slope Spline-GARCH Analyses on ETFs