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V-Lab

S&P GSCI Agricultural Spot Index APARCH Volatility Analysis

Volatility prediction for Wednesday, September 9th, 2026

1 Day

18.37%

decreased by 0.60%

1 Week

18.38%

decreased by 0.59%

1 Month

18.39%

decreased by 0.58%

Analysis last updated: Tuesday, September 8, 2026 at 11:30 PM UTC

Date Range:

from

to

6M ·

1Y ·

2Y ·

5Y ·

10Y ·

All

graph of S&P GSCI Agricultural Spot Index APARCH

News Impact Curve

How returns affect tomorrow's volatility

Volatility Forecast

How volatility evolves over time

Parameter Estimates

Jan 2, 1990 to Sep 8, 2026

Model Insight

With persistence 0.991, volatility shocks have a half-life of 78 trading days (~0.3 years), close to a unit root, so long-run forecasts are highly sensitive to this estimate. The volatility power δ = 1.66 sits below 2, so large shocks influence volatility less than quadratically, a more outlier-robust response than standard GARCH.

σ

APARCH Model

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High persistence: persistence 0.991, shock half-life ~78 daysδ = 1.66 · sub-quadratic power
ParamValuet-stat
ωconst0.0115
4.78***
αARCH0.0606
9.42***
βGARCH0.9367
158.09***
γleverage-0.0685
-1.67*
δpower1.6582
8.21***

0.991

Persistence

78d

Half-life
σ

APARCH Model

Tap to view equation

ParameterValuet-statistic
ω

const

Unconditional variance weight

0.0115
4.78***
α

ARCH

Response to squared shocks

0.0606
9.42***
β

GARCH

Volatility persistence

0.9367
158.09***
γ

leverage

Additional response to negative shocks

-0.0685
-1.67*
δ

power

Transformation power

1.6582
8.21***

Persistence:

0.991

Half-life:

78 days