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V-Lab
V-Lab

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

Volatility prediction for Monday, September 14th, 2026

1 Day

35.63%

decreased by 1.01%

1 Week

35.60%

decreased by 1.04%

1 Month

35.51%

decreased by 1.13%

Analysis last updated: Saturday, September 12, 2026 at 12:56 AM UTC

Date Range:

from

to

6M ·

1Y ·

2Y ·

5Y ·

10Y ·

All

graph of S&P GSCI Coffee 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 11, 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 22 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
ωconst0.6559
9.86***
αARCH0.0602
6.81***
βGARCH0.9084
63.97***
γi Spline Coefficients
K=3
γ1-0.0124
-5.06***
γ20.0169
4.82***
γ3-0.0055
-3.27***

0.969

Persistence

22d

Half-life
τ

Zero Slope Spline-GARCH Model

Tap to view equation

ParameterValuet-statistic
ω

const

Unconditional variance weight

0.6559
9.86***
α

ARCH

Response to squared shocks

0.0602
6.81***
β

GARCH

Volatility persistence

0.9084
63.97***
γi Spline Coefficients
K=3
γ1-0.0124
-5.06***
γ20.0169
4.82***
γ3-0.0055
-3.27***

Persistence:

0.969

Half-life:

22 days