๐ค AI Summary
This study addresses the challenge of estimating the full-support distribution of the latent instantaneous variance of asset log-prices from noisy high-frequency financial data. It proposes a nonparametric realized empirical distribution function (REDF) that consistently estimates this distribution and, based on it, develops a novel goodness-of-fit test for stochastic volatility models, exhibiting both correct size and high power. The theoretical justification relies on a double-asymptotic framework, and Monte Carlo simulations confirm the methodโs finite-sample validity. Empirical analysis reveals that while the inverse Gaussian distribution provides a reasonable fit for equity volatility, more flexible three-parameter alternatives such as the generalized inverse Gaussian may offer superior adaptability. This work represents the first nonparametric, consistent estimation of the volatility distribution from noisy high-frequency data and introduces a new diagnostic tool for stochastic volatility model evaluation.