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V-Lab

American Express Co GJR-GARCH Volatility Analysis

Volatility prediction for Monday, July 27th, 2026

1 Day

36.18%

increased by 8.55%

1 Week

36.31%

increased by 8.68%

1 Month

36.83%

increased by 9.20%

Analysis last updated: Friday, July 24, 2026 at 10:19 PM UTC

Date Range:

from

to

6M ·

1Y ·

2Y ·

5Y ·

10Y ·

All

graph of American Express Co GJR-GARCH

News Impact Curve

How returns affect tomorrow's volatility

Volatility Forecast

How volatility evolves over time

Parameter Estimates

Jan 2, 1990 to Jul 24, 2026

Model Insight

With persistence 0.997, volatility shocks have a half-life of 221 trading days (~0.9 years), close to a unit root, so long-run forecasts are highly sensitive to this estimate.

Leverage: volatility responds almost entirely to negative shocks

σ

GJR-GARCH Model

Tap to view equation

ParameterValuet-statistic
ω

const

Unconditional variance weight

0.0354
17.05***
α

ARCH

Response to squared shocks

0.0170
13.27***
β

GARCH

Volatility persistence

0.9277
747.56***
γ

leverage

Additional response to negative shocks

0.1043
26.81***

Persistence:

0.997

Half-life:

221 days