V-Lab
Proshares S&P 500 EX-Technology ETF Spline-GARCH Volatility Analysis
Volatility prediction for Monday, August 10th, 2026
1 Day
12.53%
decreased by 0.52%
1 Week
12.65%
decreased by 0.40%
1 Month
12.93%
decreased by 0.12%
Analysis last updated: Saturday, August 8, 2026 at 02:28 AM UTC
News Impact Curve
How returns affect tomorrow's volatilityVolatility Forecast
How volatility evolves over timeParameter Estimates
Sep 24, 2015 to Aug 7, 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 7 trading days.
τ
Spline-GARCH Model
Tap to view equation
| Parameter | Value | t-statistic |
|---|---|---|
ω const Unconditional variance weight | 0.8779 | 2.49** |
α ARCH Response to squared shocks | 0.0914 | 4.05*** |
β GARCH Volatility persistence | 0.8188 | 20.95*** |
Spline Coefficients
K=10
| γ1 | -0.5574 | -0.46 |
| γ2 | 1.9784 | 1.15 |
| γ3 | -2.7812 | -2.52** |
| γ4 | 2.3873 | 2.54** |
| γ5 | -2.2471 | -2.57** |
| γ6 | 2.8550 | 3.54*** |
| γ7 | -3.6833 | -5.49*** |
| γ8 | 3.7961 | 5.44*** |
| γ9 | -2.7588 | -3.43*** |
| γ10 | 1.7657 | 1.67* |
Persistence:
0.910
Half-life:
7 days
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