Estimation of the realized (co-)volatility vector: Large deviations approach

Date/heure
6 avril 2017
09:15 - 10:15

Oratrice ou orateur
Hacene Djellout

Catégorie d'évènement
Séminaire Probabilités et Statistique


Résumé

Realized statistics based on high frequency returns have become very
popular in financial economics.In recent years,
different non-parametric estimators of the variation of a log-price
process have appeared. Among them are the realized
quadratic (co-)variation which is perhaps the most well known example,
providing a consistent estimator of the integrated
(co-)volatility when the logarithmic price process is continuous. In
this paper, we propose to study the large deviation
properties of realized (co-)volatility. Our main motivation is to
improve upon the existing limit theorems such as the weak law
of large numbers or the central limit theorem which have been proved in
different contexts. Our large deviations results can
be used to evaluate and approximate tail probabilities of realized
(co-)volatility. As an application we provide the large deviations
for the standard dependence measures between the two assets returns such
as the realized regression coefficients or the
realized correlation. Our study should contribute to the recent trend of
research on the (co-)variance estimation problems, which
are quite often discussed in high-frequency financial data analysis.