CBOE S&P 500 9-Day Volatility Index Asy. Power MEM Volatility Analysis
Volatility prediction for Tuesday, July 21st, 2026
1 Day
227.65%
1 Week
221.28%
1 Month
205.02%
Analysis last updated: Tuesday, July 21, 2026 at 12:02 PM UTC
News Impact Curve
How returns affect tomorrow's volatilityVolatility Forecast
How volatility evolves over timeParameter Estimates
Oct 4, 2013 to Jul 17, 2026Model Insight
This asset shows a rare inverse leverage effect: positive returns raise next-day volatility 155% more than negative returns. Volatility rises more after gains than after losses, the reverse of the usual leverage effect and uncommon among risky assets. The volatility power δ = 1.04 sits below 2, so large shocks influence volatility less than quadratically, a more outlier-robust response than standard GARCH.
APMEM Model
Tap to view equation
| Parameter | Value | t-statistic |
|---|---|---|
ω const Unconditional variance weight | 0.8754 | 7.42*** |
α ARCH Response to squared shocks | 0.1583 | 28.31*** |
β GARCH Volatility persistence | 0.8019 | 111.97*** |
γ leverage Additional response to negative shocks | -0.4234 | -20.66*** |
δ power Transformation power | 1.0367 | 21.39*** |
Persistence:
0.929
Half-life:
9 days
Other CBOE S&P 500 9-Day Volatility Index Analyses
Other Asy. Power MEM Analyses on Volatility Indices