Toward a phase diagram for stocks

A display of the tentatively basic parameters of stocks, i.e. the daily clo sing price and the daily transaction volume is presented eliminating the ti me variable between them. The "phase diagram" looks like a triangular regio n similar to the two-phase region of traffic diagrams. The data is taken fo r two companies (SGP and OXHP) which present different long-range correlati ons in the closing price value as examined by the linearly Detrended Fluctu ation Analysis (DFA) statistical method. Substructures are observed in the "phase diagram" as due to changes in management policy, e.g. stock splits. (C) 1999 Published by Elsevier Science B.V. All rights reserved.