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V-Lab

S&P GSCI Wheat Index GJR-GARCH Volatility Analysis

Volatility prediction for Wednesday, August 26th, 2026

1 Day

30.04%

decreased by 0.69%

1 Week

29.99%

decreased by 0.74%

1 Month

29.77%

decreased by 0.96%

Analysis last updated: Tuesday, August 25, 2026 at 11:09 PM UTC

Date Range:

from

to

6M ·

1Y ·

2Y ·

5Y ·

10Y ·

All

graph of S&P GSCI Wheat Index GJR-GARCH

News Impact Curve

How returns affect tomorrow's volatility

Volatility Forecast

How volatility evolves over time

Parameter Estimates

Jan 2, 1990 to Aug 21, 2026

Model Insight

With persistence 0.991, volatility shocks have a half-life of 74 trading days (~0.3 years), close to a unit root, so long-run forecasts are highly sensitive to this estimate.

Inverse leverage: Positive returns increase volatility 82% more than negative returns

σ

GJR-GARCH Model

Tap to view equation

ParameterValuet-statistic
ω

const

Unconditional variance weight

0.0267
19.41***
α

ARCH

Response to squared shocks

0.0590
25.29***
β

GARCH

Volatility persistence

0.9449
664.50***
γ

leverage

Additional response to negative shocks

-0.0265
-7.23***

Persistence:

0.991

Half-life:

74 days