Skip to main content
V-Lab

S&P Composite 1500 Index GAS-GARCH Student T Volatility Analysis

Volatility prediction for Tuesday, July 28th, 2026

1 Day

12.26%

decreased by 0.19%

1 Week

12.43%

decreased by 0.02%

1 Month

13.06%

increased by 0.61%

Analysis last updated: Tuesday, July 28, 2026 at 12:14 AM UTC

Date Range:

from

to

6M ·

1Y ·

2Y ·

5Y ·

10Y ·

All

graph of S&P Composite 1500 Index GAS-GARCH-T

News Impact Curve

How returns affect tomorrow's volatility

Volatility Forecast

How volatility evolves over time

Parameter Estimates

Oct 31, 1994 to Jul 24, 2026

Model Insight

Volatility shocks decay with a half-life of 58 trading days, meaning a shock loses half its impact after approximately 58 days. Returns follow a Student-t distribution with v = 7.61 degrees of freedom, capturing fatter tails than a normal distribution.

𝑓

GAS-GARCH-T Model

Tap to view equation

ParameterValuet-statistic
ω

const

Unconditional variance weight

1.3181
7.24***
α

ARCH

Response to squared shocks

0.0923
38.30***
β

GARCH

Volatility persistence

0.9881
541.10***
ν

DF

Student-t tail thickness

7.6053
6.93***

Persistence:

0.988

Half-life:

58 days