V-Lab
S&P GSCI Spot Index GJR-GARCH Volatility Analysis
Volatility prediction for Monday, September 21st, 2026
1 Day
20.79%
decreased by 0.66%
1 Week
20.85%
decreased by 0.60%
1 Month
21.10%
decreased by 0.35%
Analysis last updated: Saturday, September 19, 2026 at 12:03 AM UTC
News Impact Curve
How returns affect tomorrow's volatilityVolatility Forecast
How volatility evolves over timeParameter Estimates
Jan 2, 1990 to Sep 18, 2026Model Insight
With persistence 0.996, volatility shocks have a half-life of 176 trading days (~0.7 years), close to a unit root, so long-run forecasts are highly sensitive to this estimate.
σ
GJR-GARCH Model
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High persistence: persistence 0.996, shock half-life ~176 days
| Param | Value | t-stat |
|---|---|---|
| ωconst | 0.0121 | 5.00*** |
| αARCH | 0.0677 | 4.82*** |
| βGARCH | 0.9258 | 127.19*** |
| γleverage | 0.0052 | 0.25 |
0.996
Persistence176d
Half-lifeσ
GJR-GARCH Model
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| Parameter | Value | t-statistic |
|---|---|---|
ω const Unconditional variance weight | 0.0121 | 5.00*** |
α ARCH Response to squared shocks | 0.0677 | 4.82*** |
β GARCH Volatility persistence | 0.9258 | 127.19*** |
γ leverage Additional response to negative shocks | 0.0052 | 0.25 |
Persistence:
0.996
Half-life:
176 days
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