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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

Date Range:

from

to

6M ·

1Y ·

2Y ·

5Y ·

10Y ·

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graph of BIST 30 Index GJR-GARCH

News Impact Curve

How returns affect tomorrow's volatility

Volatility Forecast

How volatility evolves over time

Parameter Estimates

Jan 2, 1997 to Aug 14, 2026

Model 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

ParameterValuet-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