V-Lab
BIST 30 Index GJR-GARCH Volatility Analysis
Volatility prediction for Wednesday, August 19th, 2026
1 Day
21.36%
decreased by 0.73%
1 Week
21.91%
decreased by 0.18%
1 Month
23.85%
increased by 1.76%
Analysis last updated: Wednesday, August 19, 2026 at 05:47 PM UTC
News Impact Curve
How returns affect tomorrow's volatilityVolatility Forecast
How volatility evolves over timeParameter Estimates
Jan 2, 1997 to Aug 14, 2026Model Insight
With persistence 0.990, volatility shocks have a half-life of 72 trading days (~0.3 years), close to a unit root, so long-run forecasts are highly sensitive to this estimate.
Leverage: Negative returns increase volatility 63% more than positive returns
σ
GJR-GARCH Model
Tap to view equation
| Parameter | Value | t-statistic |
|---|---|---|
ω const Unconditional variance weight | 0.0647 | 19.35*** |
α ARCH Response to squared shocks | 0.0675 | 18.88*** |
β GARCH Volatility persistence | 0.9015 | 366.33*** |
γ leverage Additional response to negative shocks | 0.0428 | 6.80*** |
Persistence:
0.990
Half-life:
72 days
Other GJR-GARCH Analyses on Equity Indices