Principes de finance : comparaison des approches du "noise trader" et des "marchés efficients" pour l'évaluation du prix sur les marchés financiers

On financial markets prices reflect a volume of aggregate information, thus pricing is an essential mechanism to understand financial markets. Surprisingly pricing models have only been a major research subject since the sixties. As pricing is the determination of the price, pricing models try to reflect reality and help to make good investment decisions

There is no consensus about formation of prices on financial markets and two schools of thought coexist. The first model is the efficient market theory. A market is efficient if prices on the market perfectly and instantaneity reflect all available information. Experiences to test market efficiency have produced various results and one can almost always decide that the results stand for or against markets efficiency theory. Moreover, testing markets efficiency is always testing a joint hypothesis as it is impossible to test markets efficiency without testing a pricing model.

In this essay I will try to present and compare each pricing model and to determine whether they meet their goals or not.