V-Lab
S&P GSCI Biofuel Spot Index APARCH Volatility Analysis
Volatility prediction for Wednesday, September 9th, 2026
1 Day
18.71%
1 Week
18.73%
1 Month
18.81%
Analysis last updated: Tuesday, September 8, 2026 at 11:30 PM UTC
News Impact Curve
How returns affect tomorrow's volatilityVolatility Forecast
How volatility evolves over timeParameter Estimates
Jan 16, 1995 to Sep 8, 2026Model Insight
Volatility shocks decay with a half-life of 48 trading days, meaning a shock loses half its impact after approximately 48 days. The volatility power δ = 1.53 sits below 2, so large shocks influence volatility less than quadratically, a more outlier-robust response than standard GARCH.
APARCH Model
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| Param | Value | t-stat |
|---|---|---|
| ωconst | 0.0195 | 4.27*** |
| αARCH | 0.0626 | 10.22*** |
| βGARCH | 0.9314 | 114.31*** |
| γleverage | -0.0222 | -0.51 |
| δpower | 1.5332 | 6.83*** |
0.986
Persistence48d
Half-lifeAPARCH Model
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| Parameter | Value | t-statistic |
|---|---|---|
ω const Unconditional variance weight | 0.0195 | 4.27*** |
α ARCH Response to squared shocks | 0.0626 | 10.22*** |
β GARCH Volatility persistence | 0.9314 | 114.31*** |
γ leverage Additional response to negative shocks | -0.0222 | -0.51 |
δ power Transformation power | 1.5332 | 6.83*** |
Persistence:
0.986
Half-life:
48 days
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