Statistical inference for rough volatility: Minimax Theory
Carsten Chong, Marc Hoffmann, Yanghui Liu, Mathieu Rosenbaum, Grégoire Szymanski
TL;DR
This work establishes that the parameters of rough volatility models can be inferred with optimal accuracy in all regimes, and establishes minimax lower bounds for parameter estimation and design procedures based on wavelets attaining them.
Abstract
Rough volatility models have gained considerable interest in the quantitative finance community in recent years. In this paradigm, the volatility of the asset price is driven by a fractional Brownian motion with a small value for the Hurst parameter $H$. In this work, we provide a rigorous statistical analysis of these models. To do so, we establish minimax lower bounds for parameter estimation and design procedures based on wavelets attaining them. We notably obtain an optimal speed of convergence of $n^{-1/(4H+2)}$ for estimating $H$ based on n sampled data, extending results known only for the easier case $H>1/2$ so far. We therefore establish that the parameters of rough volatility models can be inferred with optimal accuracy in all regimes.
