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V-Lab
V-Lab

AT&T Inc GARCH Volatility Analysis

Volatility prediction for Friday, September 11th, 2026

1 Day

23.55%

increased by 0.11%

1 Week

23.58%

increased by 0.14%

1 Month

23.72%

increased by 0.28%

Analysis last updated: Thursday, September 10, 2026 at 10:02 PM UTC

Date Range:

from

to

6M ·

1Y ·

2Y ·

5Y ·

10Y ·

All

graph of AT&T Inc GARCH

News Impact Curve

How returns affect tomorrow's volatility

Volatility Forecast

How volatility evolves over time

Parameter Estimates

Jan 2, 1990 to Sep 4, 2026

Model Insight

With persistence 0.991, volatility shocks have a half-life of 74 trading days (~0.3 years), close to a unit root, so long-run forecasts are highly sensitive to this estimate.

σ

GARCH Model

Tap to view equation

High persistence: persistence 0.991, shock half-life ~74 days
ParamValuet-stat
ωconst0.0240
5.02***
αARCH0.0529
8.53***
βGARCH0.9377
140.63***

0.991

Persistence

74d

Half-life
σ

GARCH Model

Tap to view equation

ParameterValuet-statistic
ω

const

Unconditional variance weight

0.0240
5.02***
α

ARCH

Response to squared shocks

0.0529
8.53***
β

GARCH

Volatility persistence

0.9377
140.63***

Persistence:

0.991

Half-life:

74 days