Trading volume in financial markets: An introductory review

In this article, I introduce a short review on the statistical and dynamical properties of the high-frequency trading volume and its relation to other financial quantities such as the price fluctuations and trading value. In addition, I compare these results — which were obtained within the framework of applications of Physics to quantitative financial analysis —with the mainstream financial hypotheses of mixture of distributions (MDH) and sequential arrival of information (SIAH).