Skip to main content
V-Lab
V-Lab

State Street SPDR Portfolio Aggregate Bond ETF GJR-GARCH Volatility Analysis

Volatility prediction for Monday, September 21st, 2026

1 Day

4.61%

increased by 0.30%

1 Week

4.62%

increased by 0.31%

1 Month

4.67%

increased by 0.36%

Analysis last updated: Friday, September 18, 2026 at 11:12 PM UTC

Date Range:

from

to

6M ·

1Y ·

2Y ·

5Y ·

10Y ·

All

graph of State Street SPDR Portfolio Aggregate Bond ETF GJR-GARCH

News Impact Curve

How returns affect tomorrow's volatility

Volatility Forecast

How volatility evolves over time

Parameter Estimates

May 30, 2007 to Sep 18, 2026

Model Insight

With persistence 0.992, volatility shocks have a half-life of 87 trading days (~0.3 years), close to a unit root, so long-run forecasts are highly sensitive to this estimate.

σ

GJR-GARCH Model

Tap to view equation

High persistence: persistence 0.992, shock half-life ~87 days
ParamValuet-stat
ωconst0.0009
4.10***
αARCH0.0651
3.68***
βGARCH0.9084
80.96***
γleverage0.0370
1.04

0.992

Persistence

87d

Half-life
σ

GJR-GARCH Model

Tap to view equation

ParameterValuet-statistic
ω

const

Unconditional variance weight

0.0009
4.10***
α

ARCH

Response to squared shocks

0.0651
3.68***
β

GARCH

Volatility persistence

0.9084
80.96***
γ

leverage

Additional response to negative shocks

0.0370
1.04

Persistence:

0.992

Half-life:

87 days