The last systemic financial crisis has reawakened the debate on the efficient nature of financial markets, traditionally described as semimartingales. The standard approaches to endow the general notion of efficiency of an empirical content turned out to be somewhat inconclusive and misleading. We propose a topological-based approach to quantify the informational efficiency of a financial time series. The idea is to measure the efficiency by means of the pointwise regularity of a (stochastic) function, given that the signature of a martingale is that its pointwise regularity equals 1/2. We provide estimates for real financial time series and investigate their (in)efficient behavior by comparing three main stock indexes.

Fractal stock markets: International evidence of dynamical (in)efficiency

Sergio Bianchi;Massimiliano Frezza
2017-01-01

Abstract

The last systemic financial crisis has reawakened the debate on the efficient nature of financial markets, traditionally described as semimartingales. The standard approaches to endow the general notion of efficiency of an empirical content turned out to be somewhat inconclusive and misleading. We propose a topological-based approach to quantify the informational efficiency of a financial time series. The idea is to measure the efficiency by means of the pointwise regularity of a (stochastic) function, given that the signature of a martingale is that its pointwise regularity equals 1/2. We provide estimates for real financial time series and investigate their (in)efficient behavior by comparing three main stock indexes.
File in questo prodotto:
File Dimensione Formato  
Bianchi-Frezza-CHAOS2017.pdf

solo utenti autorizzati

Tipologia: Documento in Post-print
Licenza: Copyright dell'editore
Dimensione 1.72 MB
Formato Adobe PDF
1.72 MB Adobe PDF   Visualizza/Apri   Richiedi una copia

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11580/65314
Citazioni
  • ???jsp.display-item.citation.pmc??? 2
  • Scopus 13
social impact