Financial information, mandatory, austere and poorly lived, financial communication has become more attractive and better controlled, serving the overall strategy of the company. They are three in number: valuation of the share price, ability to raise funds, ability to convince and retain shareholders. The Stock Exchange is certainly subject to the law of supply and demand, but this supply and this demand are closely linked to the expectations of market operators. And these expectations certainly depend on rational criteria, but also on the perception that operators have of the company in its sector. If the past results were good, if the forecasts prove satisfactory, and especially if the operators have confidence in the future of the company, the requests will be numerous, and the rating of the action will climb. Thus the price of a share is not a reflection of the book value of a company at a given moment, but a reflection of its evolution as anticipated by the stock market community.