V-Lab
S&P SmallCap 600 Index APARCH Volatility Analysis
Volatility prediction for Thursday, August 6th, 2026
1 Day
15.86%
increased by 1.18%
1 Week
16.08%
increased by 1.40%
1 Month
16.85%
increased by 2.17%
Analysis last updated: Wednesday, August 5, 2026 at 11:02 PM UTC
News Impact Curve
How returns affect tomorrow's volatilityVolatility Forecast
How volatility evolves over timeParameter Estimates
Jan 1, 1990 to Jul 31, 2026Model Insight
This asset exhibits a strong leverage effect: negative returns increase next-day volatility 300% more than equivalent positive returns. The volatility power δ = 0.94 sits below 2, so large shocks influence volatility less than quadratically, a more outlier-robust response than standard GARCH.
σ
APARCH Model
Tap to view equation
| Parameter | Value | t-statistic |
|---|---|---|
ω const Unconditional variance weight | 0.0271 | 34.80*** |
α ARCH Response to squared shocks | 0.0853 | 47.45*** |
β GARCH Volatility persistence | 0.9124 | 504.07*** |
γ leverage Additional response to negative shocks | 0.6288 | 42.48*** |
δ power Transformation power | 0.9371 | 35.98*** |
Persistence:
0.979
Half-life:
33 days
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