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V-Lab

State Street SPDR Portfolio Aggregate Bond ETF APARCH Volatility Analysis

Volatility prediction for Friday, September 4th, 2026

1 Day

3.81%

decreased by 0.14%

1 Week

3.84%

decreased by 0.11%

1 Month

3.95%

increased by 0.00%

Analysis last updated: Thursday, September 3, 2026 at 09:49 PM UTC

Date Range:

from

to

6M ·

1Y ·

2Y ·

5Y ·

10Y ·

All

graph of State Street SPDR Portfolio Aggregate Bond ETF APARCH

News Impact Curve

How returns affect tomorrow's volatility

Volatility Forecast

How volatility evolves over time

Parameter Estimates

May 30, 2007 to Aug 28, 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

APARCH Model

Tap to view equation

ParameterValuet-statistic
ω

const

Unconditional variance weight

0.0010
2.29**
α

ARCH

Response to squared shocks

0.0847
8.06***
β

GARCH

Volatility persistence

0.9088
63.22***
γ

leverage

Additional response to negative shocks

0.1162
1.80*
δ

power

Transformation power

1.9162
6.01***

Persistence:

0.992

Half-life:

87 days