V-Lab
S&P GSCI Cotton Index Zero Slope Spline-GARCH Volatility Analysis
Volatility prediction for Monday, September 14th, 2026
1 Day
25.59%
increased by 0.81%
1 Week
25.59%
increased by 0.81%
1 Month
25.60%
increased by 0.82%
Analysis last updated: Saturday, September 12, 2026 at 12:56 AM UTC
News Impact Curve
How returns affect tomorrow's volatilityVolatility Forecast
How volatility evolves over timeParameter Estimates
Jan 2, 1990 to Sep 11, 2026Model Insight
With persistence 0.993, volatility shocks have a half-life of 98 trading days (~0.4 years), close to a unit root, so long-run forecasts are highly sensitive to this estimate.
τ
Zero Slope Spline-GARCH Model
Tap to view equation
High persistence: persistence 0.993, shock half-life ~98 days
| Param | Value | t-stat |
|---|---|---|
| ωconst | 0.9533 | 10.33*** |
| αARCH | 0.0434 | 9.69*** |
| βGARCH | 0.9495 | 186.07*** |
Spline Coefficients
K=1
| γ1 | -0.0001 | -0.70 |
0.993
Persistence98d
Half-lifeτ
Zero Slope Spline-GARCH Model
Tap to view equation
| Parameter | Value | t-statistic |
|---|---|---|
ω const Unconditional variance weight | 0.9533 | 10.33*** |
α ARCH Response to squared shocks | 0.0434 | 9.69*** |
β GARCH Volatility persistence | 0.9495 | 186.07*** |
Spline Coefficients
K=1
| γ1 | -0.0001 | -0.70 |
Persistence:
0.993
Half-life:
98 days
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