American Express Co AGARCH Volatility Analysis
Volatility prediction for Friday, October 23rd, 2026
1 Day
17.06%
decreased by 0.69%
1 Week
17.69%
decreased by 0.06%
1 Month
19.87%
increased by 2.12%
Analysis last updated: Thursday, October 22, 2026 at 09:34 PM UTC
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News Impact Curve
How returns affect tomorrow's volatilityVolatility Forecast
How volatility evolves over timeParameter Estimates
Jan 2, 1990 to Oct 16, 2026Model 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.
Asymmetry: negative returns raise volatility more
σ
AGARCH Model
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High persistence: persistence 0.991, shock half-life ~74 daysAsymmetry: negative returns raise volatility more
| Param | Value | t-stat |
|---|---|---|
| ωconst | 0.0000 | 0.00 |
| αARCH | 0.0770 | 13.24*** |
| βGARCH | 0.9136 | 159.00*** |
| γleverage | 0.8407 | 6.30*** |
0.991
Persistence74d
Half-lifeσ
AGARCH Model
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| Parameter | Value | t-statistic |
|---|---|---|
ω const Unconditional variance weight | 0.0000 | 0.00 |
α ARCH Response to squared shocks | 0.0770 | 13.24*** |
β GARCH Volatility persistence | 0.9136 | 159.00*** |
γ leverage Additional response to negative shocks | 0.8407 | 6.30*** |
Persistence:
0.991
Half-life:
74 days
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