V-Lab
Russell Midcap Index APARCH Volatility Analysis
Volatility prediction for Friday, September 4th, 2026
1 Day
13.82%
1 Week
14.06%
1 Month
14.88%
Analysis last updated: Friday, September 4, 2026 at 11:25 PM UTC
News Impact Curve
How returns affect tomorrow's volatilityVolatility Forecast
How volatility evolves over timeParameter Estimates
Mar 1, 2004 to Aug 27, 2026Model Insight
This asset exhibits a strong leverage effect: volatility responds almost entirely to negative shocks. The ARCH response to positive shocks is negligible. The volatility power δ = 1.20 sits below 2, so large shocks influence volatility less than quadratically, a more outlier-robust response than standard GARCH.
APARCH Model
Tap to view equation
| Param | Value | t-stat |
|---|---|---|
| ωconst | 0.0272 | 7.62*** |
| αARCH | 0.0757 | 5.50*** |
| βGARCH | 0.9095 | 101.67*** |
| γleverage | 0.9206 | 4.23*** |
| δpower | 1.2018 | 9.41*** |
0.978
Persistence32d
Half-lifeAPARCH Model
Tap to view equation
| Parameter | Value | t-statistic |
|---|---|---|
ω const Unconditional variance weight | 0.0272 | 7.62*** |
α ARCH Response to squared shocks | 0.0757 | 5.50*** |
β GARCH Volatility persistence | 0.9095 | 101.67*** |
γ leverage Additional response to negative shocks | 0.9206 | 4.23*** |
δ power Transformation power | 1.2018 | 9.41*** |
Persistence:
0.978
Half-life:
32 days
Other Russell Midcap Index Analyses
Other APARCH Analyses on Equity Indices