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V-Lab

S&P Total Market Index GJR-GARCH Volatility Analysis

Volatility prediction for Monday, September 21st, 2026

1 Day

11.15%

decreased by 0.43%

1 Week

11.59%

increased by 0.01%

1 Month

12.96%

increased by 1.38%

Analysis last updated: Saturday, September 19, 2026 at 12:01 AM UTC

Date Range:

from

to

6M ·

1Y ·

2Y ·

5Y ·

10Y ·

All

graph of S&P Total Market Index GJR-GARCH

News Impact Curve

How returns affect tomorrow's volatility

Volatility Forecast

How volatility evolves over time

Parameter Estimates

Mar 30, 2006 to Sep 18, 2026

Model Insight

This asset exhibits a strong leverage effect: volatility responds almost entirely to negative shocks. The ARCH response to positive shocks is negligible.

σ

GJR-GARCH Model

Tap to view equation

Leverage: volatility responds almost entirely to negative shocks
ParamValuet-stat
ωconst0.0336
3.74***
αARCH0.0103
0.38
βGARCH0.8638
45.45***
γleverage0.1980
5.18***

0.973

Persistence

25d

Half-life
σ

GJR-GARCH Model

Tap to view equation

ParameterValuet-statistic
ω

const

Unconditional variance weight

0.0336
3.74***
α

ARCH

Response to squared shocks

0.0103
0.38
β

GARCH

Volatility persistence

0.8638
45.45***
γ

leverage

Additional response to negative shocks

0.1980
5.18***

Persistence:

0.973

Half-life:

25 days