Wavelet based sample entropy analysis: A new method to test weak form market efficiency
In this article, we analyze informational efficiency in daily returns of NASDAQ, DJIA and S&P 500 indices ranging from 04-01-1980 to 12-09-2013.We replace the traditional coarse graining method used in multi-scale entropy analysis by a Maximal Overlap Discreet Wavelet Transform decomposition and extract Sample entropy measure across different times