Price dynamics, social networks and communication

•We develop a stock price dynamics model considering social network communication in financial markets.•The movement of prices depends on the topologies of social networks and the communication effect.•A price self-organising system is established by introducing a nonlinear feedback effect of historical returns.•Bubbles and crashes are explained as alternate strong positive and negative self-reinforcing processes of prices.

A stock price dynamics model is developed in consideration of social network communication in financial markets. Considering a nonlinear feedback effect of price returns, we establish a self-organising system of price dynamics. Results show that the movement of prices depends on the topologies of networks and the communication effect. Furthermore, the self-reinforcing feature of price dynamics is explored and bubbles and crashes are explained as alternate strong positive and negative self-reinforcing processes of prices.