Alphabet Inc APARCH Volatility Analysis
Volatility prediction for Thursday, October 22nd, 2026
1 Day
29.11%
1 Week
29.69%
1 Month
31.67%
Analysis last updated: Wednesday, October 21, 2026 at 09:13 PM UTC
News Impact Curve
How returns affect tomorrow's volatilityVolatility Forecast
How volatility evolves over timeParameter Estimates
Aug 19, 2004 to Oct 16, 2026Model Insight
Volatility shocks decay with a half-life of 24 trading days, meaning a shock loses half its impact after approximately 24 days. The volatility power δ = 0.50 sits below 2, so large shocks influence volatility less than quadratically, a more outlier-robust response than standard GARCH.
APARCH Model
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| Param | Value | t-stat |
|---|---|---|
| ωconst | 0.0450 | 3.11*** |
| αARCH | 0.0816 | 5.16*** |
| βGARCH | 0.9050 | 44.68*** |
| γleverage | 0.1884 | 1.29 |
| δpower | 0.5000 | 2.85*** |
0.972
Persistence24d
Half-lifeAPARCH Model
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| Parameter | Value | t-statistic |
|---|---|---|
ω const Unconditional variance weight | 0.0450 | 3.11*** |
α ARCH Response to squared shocks | 0.0816 | 5.16*** |
β GARCH Volatility persistence | 0.9050 | 44.68*** |
γ leverage Additional response to negative shocks | 0.1884 | 1.29 |
δ power Transformation power | 0.5000 | 2.85*** |
Persistence:
0.972
Half-life:
24 days
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