V-Lab
Borsa Istanbul 100 Index GJR-GARCH Volatility Analysis
Volatility prediction for Tuesday, August 25th, 2026
1 Day
21.29%
decreased by 0.56%
1 Week
21.73%
decreased by 0.12%
1 Month
23.39%
increased by 1.54%
Analysis last updated: Monday, August 24, 2026 at 03:04 PM UTC
News Impact Curve
How returns affect tomorrow's volatilityVolatility Forecast
How volatility evolves over timeParameter Estimates
Jan 1, 1990 to Aug 21, 2026Model Insight
With persistence 0.997, volatility shocks have a half-life of 262 trading days (~1.0 years), close to a unit root, so long-run forecasts are highly sensitive to this estimate.
σ
GJR-GARCH Model
Tap to view equation
| Parameter | Value | t-statistic |
|---|---|---|
ω const Unconditional variance weight | 0.0426 | 17.18*** |
α ARCH Response to squared shocks | 0.0670 | 16.00*** |
β GARCH Volatility persistence | 0.9251 | 401.33*** |
γ leverage Additional response to negative shocks | 0.0105 | 1.43 |
Persistence:
0.997
Half-life:
262 days
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