Nonconstant Variance

Definition

Nonconstant variance, frequently identified as heteroskedasticity, describes a condition in financial time series where the dispersion of price fluctuations is not uniform over time. In cryptocurrency markets, this phenomenon manifests as volatility clustering, where high-activity periods generate wider swings compared to stagnant intervals. Quantitative analysts must account for this instability because standard statistical models that assume a fixed variance will systematically underestimate risk during turbulent phases.