V-Lab
TLT Percentage Price Volatility Index Zero Slope Spline-GARCH Volatility Analysis
Volatility prediction for Friday, August 21st, 2026
1 Day
86.79%
decreased by 0.61%
1 Week
86.86%
decreased by 0.54%
1 Month
87.01%
decreased by 0.39%
Analysis last updated: Friday, August 21, 2026 at 11:36 AM UTC
News Impact Curve
How returns affect tomorrow's volatilityVolatility Forecast
How volatility evolves over timeParameter Estimates
Jan 2, 2004 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 6 trading days.
τ
Zero Slope Spline-GARCH Model
Tap to view equation
| Parameter | Value | t-statistic |
|---|---|---|
ω const Unconditional variance weight | 0.9594 | 7.50*** |
α ARCH Response to squared shocks | 0.1528 | 5.07*** |
β GARCH Volatility persistence | 0.7423 | 15.08*** |
Spline Coefficients
K=5
| γ1 | -0.0401 | -1.67* |
| γ2 | 0.0487 | 1.35 |
| γ3 | 0.0297 | 1.07 |
| γ4 | -0.0838 | -3.11*** |
| γ5 | 0.0613 | 3.15*** |
Persistence:
0.895
Half-life:
6 days
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