In this paper, we describe market in the projective geometry language and give the definition of a matrix of market rate, which is related to the matrix rate of return and the matrix of judgements in the Analytic Hierarchy Process (AHP). We use these observations to extend the AHP model to the...

Co-movements of stock price fluctuations are described by the cross-correlation matrix C. The application of random matrix theory (RMT) allows to distinguish between spurious correlations in C due to measurement noise and true correlations containing economically meaningful information. By...

We discuss the time evolution of quotation of stocks and commodities and show that they form an Ising chain. We show that transaction costs induce arbitrage risk that is usually neglected. The full analysis of the portfolio theory is computationally complex but the latest development in quantum...

A simple model of a buying–selling cycle is proposed. It is based on a notion of a profit intensity. Supply and demand curves and geometrical interpretation are discussed in this context.

Most parameters used to describe states and dynamics of financial market depend on proportions of the appropriate variables rather than on their actual values. Therefore, projective geometry seems to be the correct language to describe the theater of financial activities. We suppose that the...