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V-Lab

State Street SPDR Bloomberg 1-3 Month T-Bill ETF GARCH Volatility Analysis

Volatility prediction for Tuesday, July 21st, 2026

1 Day

0.31%

unchanged at 0.00%

1 Week

0.31%

unchanged at 0.00%

1 Month

0.31%

unchanged at 0.00%

Analysis last updated: Monday, July 20, 2026 at 09:36 PM UTC

Date Range:

from

to

6M ·

1Y ·

2Y ·

5Y ·

10Y ·

All

graph of State Street SPDR Bloomberg 1-3 Month T-Bill ETF GARCH

News Impact Curve

How returns affect tomorrow's volatility

Volatility Forecast

How volatility evolves over time

Parameter Estimates

May 30, 2007 to Jul 17, 2026

Model Insight

With persistence 0.995, volatility shocks have a half-life of 129 trading days (~0.5 years), close to a unit root, so long-run forecasts are highly sensitive to this estimate.

σ

GARCH Model

Tap to view equation

ParameterValuet-statistic
ω

const

Unconditional variance weight

0.0000
α

ARCH

Response to squared shocks

0.0205
6.12***
β

GARCH

Volatility persistence

0.9742
320.98***

Persistence:

0.995

Half-life:

129 days