Before revision:  We report results of the analysis\par  performed on high-frequency data of the Nasdaq Composite, Dow Jones Industrial Avg and Standard \& Poor 500 indexes downloaded from the Bloomberg terminal www. bloomberg.com/professional. Both raw and sampled data series have been analysed for a broad range of horizons M, varying from one to twelve months over the year 2018.
After revision:  We report results of the analysis\par performed on high-frequency data of the Nasdaq Composite, Dow Jones Industrial Avg and Standard \& Poor 500 indexes downloaded from the Bloomberg terminal . The cluster entropy S(\tau,n) is analysed in raw and sampled data series have been analysed for a broad range of horizons M, varying from one to twelve months over the year 2018.