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V-Lab

Ishares S&P 500 EX S&P 1 ETF Zero Slope Spline-GARCH Volatility Analysis

Volatility prediction for Monday, August 17th, 2026

1 Day

13.69%

unchanged at 0.00%

1 Week

13.69%

unchanged at 0.00%

1 Month

13.69%

unchanged at 0.00%

Analysis last updated: Saturday, August 15, 2026 at 02:35 AM UTC

Date Range:

from

to

6M ·

1Y ·

All

graph of Ishares S&P 500 EX S&P 1 ETF S0GARCH

News Impact Curve

How returns affect tomorrow's volatility

Volatility Forecast

How volatility evolves over time

Parameter Estimates

Jul 9, 2025 to Aug 14, 2026

Model Insight

This model fits a time-varying baseline (a spline), so volatility mean-reverts toward a slowly-shifting long-run level rather than a constant. Short-run deviations decay with a half-life of 35 trading days.

τ

Zero Slope Spline-GARCH Model

Tap to view equation

ParameterValuet-statistic
ω

const

Unconditional variance weight

0.9775
4.10***
α

ARCH

Response to squared shocks

0.0000
0.00
β

GARCH

Volatility persistence

0.9806
24.08***
γi Spline Coefficients
K=1
γ1-0.1367
-0.45

Persistence:

0.981

Half-life:

35 days