  Using a relationship between the moments of the probability distribution of
times between the two consecutive trades (intertrade time distribution) and the
moments of the distribution of a daily number of trades we show, that the
underlying point process generating times of the trades is an essentially
non-markovian long-range memory one. Further evidence for the long-range memory
nature of this point process is provided by the powerlike correlation between
the intertrade time intervals. The data set includes all trades in EESR stock
on the Moscow International Currency Exchange in January 2003 - September 2003
and in Siemens, Commerzbank and Karstadt stocks traded on the Xetra electronic
stock exchange of Deutsche Boerse in October 2002.
