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V-Lab
V-Lab

S&P GSCI Spot Index Zero Slope Spline-GARCH Volatility Analysis

Volatility prediction for Wednesday, September 9th, 2026

1 Day

20.07%

decreased by 0.44%

1 Week

20.21%

decreased by 0.30%

1 Month

20.70%

increased by 0.19%

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 Spot Index S0GARCH

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

This model fits a time-varying baseline (a spline), so volatility mean-reverts toward a slowly-shifting long-run level rather than a constant. Short-run deviations decay with a half-life of 40 trading days.

τ

Zero Slope Spline-GARCH Model

Tap to view equation

Time-varying baseline: volatility reverts to a slowly-shifting spline trend
ParamValuet-stat
ωconst0.7557
5.19***
αARCH0.0708
7.56***
βGARCH0.9122
91.89***
γi Spline Coefficients
K=4
γ10.0203
2.89***
γ2-0.0402
-4.09***
γ30.0308
5.05***
γ4-0.0140
-3.13***

0.983

Persistence

40d

Half-life
τ

Zero Slope Spline-GARCH Model

Tap to view equation

ParameterValuet-statistic
ω

const

Unconditional variance weight

0.7557
5.19***
α

ARCH

Response to squared shocks

0.0708
7.56***
β

GARCH

Volatility persistence

0.9122
91.89***
γi Spline Coefficients
K=4
γ10.0203
2.89***
γ2-0.0402
-4.09***
γ30.0308
5.05***
γ4-0.0140
-3.13***

Persistence:

0.983

Half-life:

40 days