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CBOE S&P 500 9-Day Volatility Index GJR-GARCH Volatility Analysis

Volatility prediction for Friday, October 2nd, 2026

1 Day

177.26%

decreased by 2.29%

1 Week

177.96%

decreased by 1.59%

1 Month

180.16%

increased by 0.61%

Analysis last updated: Friday, October 2, 2026 at 11:31 AM UTC

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Date Range:

from

10/01/2024

to

10/01/2026

6M ·

1Y ·

2Y ·

5Y ·

10Y ·

All

graph of CBOE S&P 500 9-Day Volatility Index GJR-GARCH

News Impact Curve

How returns affect tomorrow's volatility

Volatility Forecast

How volatility evolves over time

Parameter Estimates

Jan 3, 2011 to Sep 25, 2026

Model Insight

Volatility shocks decay with a half-life of 19 trading days, meaning a shock loses half its impact after approximately 19 days.

σ

GJR-GARCH Model

Tap to view equation

Shock decay: Shocks decay with a 19-day half-life
ParamValuet-stat
ωconst5.0000
2.04**
αARCH0.0568
2.95***
βGARCH0.9356
58.55***
γleverage-0.0568
-1.55

0.964

Persistence

19d

Half-life
σ

GJR-GARCH Model

Tap to view equation

ParameterValuet-statistic
ω

const

Unconditional variance weight

5.0000
2.04**
α

ARCH

Response to squared shocks

0.0568
2.95***
β

GARCH

Volatility persistence

0.9356
58.55***
γ

leverage

Additional response to negative shocks

-0.0568
-1.55

Persistence:

0.964

Half-life:

19 days