S&P Composite 1500 Index AGARCH Volatility Analysis
Volatility prediction for Tuesday, October 27th, 2026
1 Day
13.41%
decreased by 1.09%
1 Week
13.76%
decreased by 0.74%
1 Month
14.86%
increased by 0.36%
Analysis last updated: Monday, October 26, 2026 at 11:02 PM UTC
Press Delete or Backspace to remove this series.
News Impact Curve
How returns affect tomorrow's volatilityVolatility Forecast
How volatility evolves over timeParameter Estimates
Oct 31, 1994 to Oct 23, 2026Model Insight
The news-impact curve is shifted (γ = 0.62) so that negative returns raise next-day volatility more than positive returns of the same size. The gap is largest for small shocks and narrows for larger ones.
σ
AGARCH Model
Tap to view equation
Asymmetry: negative returns raise volatility more
| Param | Value | t-stat |
|---|---|---|
| ωconst | 0.0000 | 0.00 |
| αARCH | 0.1139 | 7.06*** |
| βGARCH | 0.8529 | 49.23*** |
| γleverage | 0.6184 | 4.55*** |
0.967
Persistence21d
Half-lifeσ
AGARCH Model
Tap to view equation
| Parameter | Value | t-statistic |
|---|---|---|
ω const Unconditional variance weight | 0.0000 | 0.00 |
α ARCH Response to squared shocks | 0.1139 | 7.06*** |
β GARCH Volatility persistence | 0.8529 | 49.23*** |
γ leverage Additional response to negative shocks | 0.6184 | 4.55*** |
Persistence:
0.967
Half-life:
21 days
Other S&P Composite 1500 Index Analyses
Other AGARCH Analyses on Equity Indices